I get that you want to help, but be careful with that. You are not a new pair of shoes to be thrown away when used enough.
Keeping a relationship in any form going, just because you want to help is not always a healthy relationship, it can easily turn into one party using the other party. I’ve seen it swing both ways and it’s not pretty.
It actually sounds like that person needs professional help. If you are not a professional, don’t get involved.
Do you have enough normal relationships on your own? And what will happen with those if you have to spend a lot of time on this particular person?
Wanting to help is a natural instinct, but if this person does not seem to build long lasting relationships with anyone there is probably a good reason for that. Trying to keep contact going with somebody like that could easily drain your energy and more. So please be careful.
There are people who did not stand at the front of the line when intelligence was gifted . But that guy wasn’t even invited at all…