I am seeking specifically-Jewish wisdom on the following question. Our rabbis have something to say on just about every aspect of life, but I'm not sure where I should be looking (or even what keywords, really) for this one.
There's someone I used to have a decent friendship with, but over time things degenerated and we both did things we'd now prefer we hadn't done. (I think more of that came from the other person, but of course perspectives are weird.) Recently this person did something I found very hurtful and I made myself scarce. The person has now (unprompted by me) expressed regret, apologized, and said that if we can't be friends yet can we at least not be enemies? I don't want to be enemies either, and responded by saying that (and accepting the apology).
My question is: what can I do to improve this relationship? I can't just pretend that all the hurt didn't happen; it did, a fair bit of it remains unaddressed, trust has been damaged, and I'm human. So I'm concerned about being hurt further, but I'd like to be able to improve on where we are now.
What interpersonal or spiritual practices should I be trying to apply? Is there recommended reading in this area?
In case it matters, the other person is not Jewish (and so is not bound by any halacha that might otherwise apply).