I think you should set a goal for yourself & make it the focus of almost all your attention. To me it sounds like UCLA is where you belong. You're 18 & an adult in many ways. Your mom should be supporting you achieving that goal as it would be something to be proud of. Sorry about the kitty, that would suck for anyone, but if your mom took it that hard, she sounds pretty lonely & seems to maybe be clinging too much to you.
If you got grants, did you check into loans to cover the rest? My daughter graduated last December. She did her whole college years on grants & loans. I just finally paid off all my loans after being a flake for years, but I helped my daughter with some occassional expenses & emergencies, but she did it pretty much by herself. She has debt now, but also has a great job.
If you feel like you were meant to be at UCLA, you can get there. You didn't get all those grants for being a looser, so take courses this semester that will transfer for credit in UCLA, find a counseler over there to believe in you & a financial aid person, & just do it. If your mom won't let go & be an encouraging force in your life now for achieving your young adult goals, then don't discuss them with her. Don't let anyone hold you back. Give your self-esteem a major shot in the arm by choosing one small goal at a time & GO GET IT! Just take it one day at a time... make sure your acceptance is still good next semester, or next fall.. whatever, then get loans lined up, even get a job there in the summer & start getting geared up before classes start. You part own a house? When your gone, maybe your mom will want to rent a room? she will be less needy for you top hang around, & maybe your share will justify some rental incom... get her to refinance & pull some cash out, rates are low now... she could even buy you out of your portion to free up expenses for your tuition at UCLA... even get an investment property near campus from your mom buying out your share, live in it for 4 years, graduate, sell it for a profit... dream big & go make something of yourself while you're still young. You can wallow in self pity later, right now you are young, take the world by the tail & make it your playground! Where would this boyfriend be if you were in UCLA? If he don't have time for you, don't waste anymore on him. You love him? make him show you he deserves it... sounds like he's not doing that at the moment.
OK I'm all opinionated out... hope it don't come off as anything but the encouragement it was intended to be.