Welcome here to the support Forum, it has taken a while for you to get an answer to your ;post, which would have been most discouraging, however I'm afraid our system does not always work as well as we would like. Please be certain it is nothing to do wiht you personally or your topic.
I guess there are several thngs all mixed up here and it is no wonder you feel uncertain as to what's the best thing to do.
Let's put it as the most basic level. You are thinking of resuming a relationship with someone you love, not somebody who is a stranger, but somebody it sounds like you know very well.
Relationships -as opposed to casual flings - really do need to have some sort of balance. Both persons need not only to love the other person, want to care for them, ease their path though life in their difficult times, and trust them.
Taking on the position of carer for someone who needs psychological help is a very different proposition, without the care coming back it is a sterile and exhausting thing. Expecting to be treated badly is bad for anyone.
You have not painted a good picture of your friend who appears to have been cruel and thoughtless, not loving and caring. You are already talking about how to protect yourself! That is no way to start out.
For this post I've let to one side the very real problems relating to how some misguided people regard LBTQI+ and also religion.
I think I've said enough for one day -other than to say there is no shame for you, if you feel any it is the unfeeling attitudes of others affecting you.
Would you like to come back and tell me that you think