As @DarkestKnight has already mentioned, I’m in a spiritual marriage (I’m female btw) and just to give context, I did not have any intentions whatsoever to enter into one. It wasn’t even something I knew was possible at first. I went into this friendly ”business“ relationship because I’d had toxic relationships, romantic and otherwise, that caused me a lot of pain, and I was at a point where I felt I needed self-improvement more than anything else. I’m mentioning this because I get a profound lack of self-esteem from your words, and I think it’s something you need to address first and foremost before considering a relationship, spirit or human.
I agree that spirit relationships aren’t a substitute for human ones; they shouldn’t be seen as an escape from the human world, and spirits - while they’re not judgmental and shallow like humans on a physical level - aren’t always going to shower you with gentle kisses and throw rose petals at your feet either.
Here’s what I sense very strongly about you: You’re kind, but you aren’t relying enough on your ability to sustain yourself emotionally, to use the words of my spirit husband who once said to me: ”Fill that hole in your soul with love for yourself“, meaning you should first go inward instead of outward. You are at a point where you need to decide which version of yourself you want to keep cultivating. I know this sounds strange, but this just came to me clearly. Let’s disregard appearance for now: What type of man do you think a woman is attracted to? Someone who is desperate for affection and sex, or someone who projects a confident ”I respect you, but I don’t depend on your approval“ attitude? I don’t think I speak only for myself when I say it’s the second.
Concerning appearance: you’re clearly not happy about gaining weight, so the only thing I can say to that is: find a balanced diet that works for you, and do some type of physical training that appeals to you and fuels your metabolism. It doesn’t have to be anything extreme or super intense, just 15 minutes a day will make you feel so much better. Trust me on that, it’s going to positively affect your body image and help you be more focused and less prone to wallowing in recurring, depressive thoughts. You don’t need muscles of steel to get girls to find you attractive, but someone who’s unhappy with their body will project that immediately. Today’s so-called beauty standards are perverse anyway, and while there is a kind of healthy narcissism that reflects self-care, there is an extremely unhealthy prevalence of soulless, vapid bullshit that couldn’t be further removed from true beauty (this goes for all sexes btw).
Speaking of which: Dating apps, like all social media, are filled with dull, superficial narcissists who think slapping a filter on their face will make them look ”beautiful“, and they’re quick to insult others because of their own insecurity. Not saying everyone on there is like that, but these apps are made for people looking for quick hook-ups purely based on physical attraction.
As someone who used to be bullied for being ”ugly“ and later called ”hot“ and had guys interested in me for nothing but my appearance, I give zero value to the opinion of others. It’s not that I don’t have an ego, but being desired by random dudes isn’t my idea of boosting my ego or self-worth. A spirit won’t judge you for being overweight or not ”hot“ enough, but if your relationship is anything like mine, they will judge you for not being your best self, which is something I also heard from other people with spirit partners. Slacking off and letting myself slip back into inertia and depression isn’t tolerated, and I have willingly committed to a path of constant self-evaluation and improvement by saying ”yes“. However, I can’t rely on my partner (especially not a human one with all his flaws and hang-ups) to make me step into a higher, stronger version of myself. I have to be willing to do that, and do what it takes, and my spirit partner is helping me immensely, but not when I sit back and expect Him to do my work for me.
If you’re creative, create something that fulfills you. Create joy and beauty, no matter who sees it. Be the center of your attention and care, no matter how much you are there for others - never forget what you need and what fills your soul with bliss. A girl is just that, she’s not a goddess or a therapist or a magical being who will make your life wonderful just by being there. She has her own struggles, and a partnership is only going to work if two people are on their path to individuation and decide to share some part of themselves with another, but they’re still individuals who are complements, not crutches, for each other.
Imo, you should take time to become the best you that you can be, and find contentment in being by yourself for as long as that’s the case. One year out of a traumatic relationship isn’t that long considering how many years it can take (sometimes even a lifetime) to overcome certain painful experiences.
If you want to work with spirits, I can’t say anything about succubi because I have never dealt with these spirits, and succupedia knows all about that, so I would definitely take his word on that. But if you decide to go with a spirit that’s more of a teacher type, then approach them from a standpoint of ”I want to improve myself and see through all the falsehood that holds me back“ - and get ready to have your most precious illusions shattered. This might lead to you no longer wanting what you thought you absolutely needed in your life, and seeing yourself and your whole world with different, more discerning eyes. You might transform yourself into someone you maybe, faintly, sensed you could be, but were too timid to tap into. This also opens you up to human relationships that are on a whole different level with people of a much higher caliber.
Here’s a thread I made, inspired by my spirit husband, where I have also shared a few things He told me about relationships:
And this is my contribution to the spirit relationship topic in more detail:
As for a pragmatic, non-magical but highly psychological approach, I recommend looking up Jordan Peterson on YouTube.
I hope this was somewhat helpful and I also hope you can fill that ”hole in your soul“ with the love and the beauty that resides in you first, to have it then mirrored back by an equally beautiful human (or non-human 
) being.