First off, I should say that all of this is fairly unlikely. Magickal practice of the kind we do here is still quite rare, unless these people that you are friends with/dating were all met in a witches coven or something. Outside of that, the likelihood that someone is casting magick on you is slim imo. What this is is a classic case of hypergamy. You meet a girl, and she likes you because you live a superior lifestyle to hers, but once you built her up to the point that her lifestyle was equal to or better than yours, you lost that uniqueness in her eyes that made you attractive in the first place (ie. the power/status differential). It’s something you need to be ever vigilant of. If you’re going to do something for a girl you like, it can never be for free. She needs to earn it somehow through actions that benefit you. You have to lay it out from the get-go what your demands in return for your services are, or she just wont respect you or your time…and it sounds like that’s exactly what happened.
In any event, what’s done is done and you can’t change that now, so lets talk magick. I think you should first focus on your own financial situation and rebuild yourself to your former glory. Once you’ve done that, then I’d turn my attention to revenge. If you live at home with folks who are anti-magick…my suggestion is to operate while they are asleep. They can’t be awake watching what you are doing 24/7. I’d wait until 3am in the morning and head to the basement (if you live in a house) or the washroom with the door closed. I may even sneak out of the house and go to some secluded park. Point is…there’s always a way to hide yourself…unless you’re literally imprisoned.
Once you’ve picked your spot, you’ve gotta pick the right magick. I think the book Demons of Magick by Gordon Winterfield would do you some good. It seems to work very well for newcomers into magick, and the ebook is fairly cheap on Amazon. Or perhaps you can do a simple petition spell. You can find instructions on how to do that here. I’d petition Bune to help improve your financial situation…and I would advise you do the same petition ritual to bune for 7 days in a row. By the end of the 7 days, you’ll hopefully feel confident that you’ve done all that you could magick-wise and you’ll forget about the ritual, which is important. Speaking of which, I’d also read through this several times to ensure that once you’ve finished doing the magick, you don’t sabotage it with your thoughts.