Hi, It is very difficult to live with someone who is emotionally neglectful or abusive, regardless of the money. I know that is the reason many people stay with someone, but it can cause so much depression and anxiety. If you are planning to let him share expenses only for financial reasons, you can work to learn to set boundaries with him. or possibly consider seeking out another roomie. You may also be able to qualify for a more reduced rent since the Governmemt housing is usually based on your income.
Look at some other options before finalizing this deal, since you are already experiencing anxiety, and apprehension. Let me know if you have further questions. Thanks, Gina