You told your mom the truth so the cat is out of the bag. That was rash but understandable.
Now mom is forcing you to deal with the consequences. Is your dad in the picture? If he is not PIMI he may buy you some time.
You can lie your way out of it as previously suggested... but this will compromise personal integrity.
Another option is to come clean, disassociate yourself mentally, find a place to stay and expect your mom to shun you for the next 20 years. Could you handle this?
I'm glad to hear you still believe in marriage. Can you rent a room or board with someone temporarily...no strings attached.
You are in your 20s, you have a job. It may be time to gird your loins, get tough on yourself and the cult and make it on your own.