Blaming kindness is another skew to your mindset which is gradually shifted in the duration of an abusive relationship. Think about it, you are blaming your kindness for abuse - that's how much he has done a number on you.
If you are not ready to go yet. Carve out some time where you are safe and comfortable to not be thinking about him at all. Think about you as an individual, what you want, pretend he is not a factor.
Syphen some of your money into a private account or leave cash and important belongings with your friend. All the while just tell yourself this is just incase.
Then, sit and think really hard about where your line is - I had a line my abusive partner knew he couldn't cross and a line that I told myself would be the point I would have no choice but to leave him and promised myself I would stick to it.
My line was really low down actually - I put up with a lot. But having a clear boundary, forced action. It could be anything sexual abuse, a hit to the face, cheating with someone you know, being hospitalised.
Keep working on your self esteem and confiding in your friend, ask her to keep her door open even if you get flaky over it all. Hopefully you will manage to get away before you get even close to your line.
He may have completely legitimate excuses and reasons for poor actions. You still don't deserve it. You may feel you are worthless. You still don't deserve it. You might think of times you brought it on or also behaved badly. You still don't deserve it.
It is not your fault.
Lastly, if you leave, a good way to stay strong is to tell those around you EVERYTHING. Your bank, your family, school, neighbours, friends. 1. They will remind you that it was him not you and 2. You will be embarrassed to resume contact with him knowing that everyone around you is aware what he put you through. Also if neighbours see him or hear anything they will be more likely to call police.
Contact different support networks such as victim support and women's aid. Spend a good year working solely on your self and don't let anybody make you feel bad for grieving your relationship. Just because he was an arse doesn't mean that you won't be sad about it ending. Remind yourself however, that you are mostly grieving about how it SHOULD have been.
Once you have healed things won't be perfect but you will feel free, you will be the perfect person to empathise with and help others in your situation.