The first 'incident' was sexual assault with intent to commit rape. The second was rape by coercion. What you need to do is ask yourself "What would I call it if this was done by a stranger, by an acquaintance, or by a 'date'. Would you 'downplay it' in those circumstances? It is no different just because it was done by a spouse/partner.
As far as 'ducks'. Based on no shared home ownership and no kids:
1- Sort tenancy. Do you want/can you afford to stay where you are? The easiest thing would be to just move yourself if you can. Can you contact the LL or HA about getting your name off the tenancy? If you're attached to the place, remember that you can't make him leave as long as the tenancy has his name on it and you probably can't get his name off.
2-Review debt. What are you liable for? Joint credit cards, loans, etc. I'm in the US and I know that joint debt liability in the UK appears to be very different in the US so I don't know what's considered joint and what's considered separate.
3-Separate finances. Get your own account and have your paycheck paid into that account. Take 50% of any savings and deposit it in an account in your name. You can choose to deposit an amount in the joint account to cover bills/rent if you choose to. Or you can 'divvy up' the bills with him so each is paying an equal amount. Be aware though, you will need to be sure that the bills are being paid either way.
4-Legal advice. At this point you need legal advice regarding ending the joint tenancy and/or getting him out and what is considered joint debt.
I, too, came from a family where divorce was not the 'done thing'. But my happiness was worth just as much to me as the happiness of the family members who would 'tut' at me. In fact, it was worth much more. They weren't living in my life, I was. And if I was unhappy, it didn't affect them but it surely affected me!!!