I will never understand this thing about wanting your exes back so bad… People come and go. Sometimes it hurts, but it’s alright - that’s how relationships work. Learn everything you possibly can from the experience and move on.
And yes - I have been in this situation - when things went bad with the love of my life (or at least I thought she was back then), and we broke up, I was on the verge of killing myself. I was literally walking around in my room with a knife thinking how I was gonna do it and all that shit. And I wasn’t a 14yo emo - I was a 19yo person, with a job and a bright mind and future. After a few hours of doing this and crying my eyes out, I finally decided - don’t end myself literally, but end this person, who would go to such extremes for shit like this, kill the childish bitch I was, perform a “Personality Suicide”, as I came to call it later.
It took a couple years but I finally got over her. I even had an interesting regression session where I found out that she’s been with me in every life, where I was a witch/mage/etc., and she has been acting like a sort of a catalyst for my magickal powers. She comes - stirs shit up so badly, that I’m left questioning my whole existence, until I finally decide to die and be reborn as a stronger, better, magickal being. If it wasn’t for her, I most likely wouldn’t be here typing this.
What i’m trying to say is this: Learn from the experience, from your mistakes - “kill” the person, who let her go. Become the best version of you, get your shit together and make sure that the next time you find “The One”, you are “worthy” and capable of seizing it, doing it right.
Forgive her, forgive yourself - that’s the best advice I can give you.
I know this is not what you came here for, but it’s honestly the right way to act - psychologically and emotionally.
Now - on the topic of your magick - seems to me like you’ve been focusing too much on the outcome. One of the first “rules” of magick I learned was: “Never lean on results, cause when you lean on something, you only push it away from you.” Trust yourself and your capabilities, and if it is not working as intended - look within and find the reasons why.
No one here can tell you why it’s not working - you hold the answers.
Sorry for the long post and for the sob story, I felt it was needed to get my point across - to show you I’ve been where you are. It gets better, trust me. All of this is part of life.
P.S.: @truewerewolf and @eliana gave awesome advises as well.