It sounds like you are still upset about something, like your mom's death, so you need her at some level. But she has broken your trust at least twice, which I think has you somewhat resentful. I don't see a reason to continue with her, as she is not really helping you grow as a person and reach your potential.
I rarely say couples should break up, but you seem so upset by her, that you need to get away from her. I think you can find someone better for you, that will give you what you need. I know it's hard, but you have to date 10 girls before you find a really good one. Keep that in mind.
You need to be strong when you two break up. I hope only you are on the lease, for Pete's sake. That makes it simpler to kick her out. Give her time to find an apartment, though, like 30 days.
I have a long time interest in psychology, specializing in relationship dynamics for 30 years.
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