Thanks for sharing this experience. Unfortunately, I doubt this is a situation with which I can be of much help since I have no 1-to-1 on-line contacts and I don't even own a smart phone. (I'm essentially what you might call an urban hermit.)

You asked if you should have apologized in the first place. Personally, I think a sincere apology seldom (if ever) hurts as long as apologizing doesn't become a habit. (Some people fall into the habit of apologizing for everything and that can become problematic.) My own perspective, with regard to what you wrote here is simply that in-person relationships can be difficult enough to navigate. On-line relationships are (I would presume) even more difficult. For one thing, you don't really know much of anything about this person you've been in contact with, not relative to the totality of her life. Plus, so much of human interaction includes facial expression & body language in addition to the words that are spoken and voice inflection. None of these " communication aids" are available via text.

The other thing I noted, in your post was you mentioning having become angry, passive-aggressive, or defensive at various points in your communication with this person. This suggests to me the possibility that you may perhaps be trying a bit too hard and hoping for too much too soon? I don't know who was right and who was wrong here. My inclination would be to say neither of you was at fault. This was simply indicative of the difficulties that can arise in these types of situations. (I will add, however, that it does seem this person you've been in touch with does seem a bit rigid for my money, so to speak. I don't think your question about giving money to homeless people was out-of-line nor should it have engendered the kind of reactivity you encountered. But, there again, you don't know what's behind the response you received. Perhaps there's a back-story here of which you are unaware.)

The other thing you asked was with regard to what you should do now. My thought on that subject would be that, at this point, you have to respect this person's request that contact between the two of you be limited to group calls. Anything more, at this stage, would probably come off as being intrusive and potentially just make matters worse. Simply continue participating in the group and, perhaps with time, the relationship between you and this individual will rekindle... perhaps not. But, at least from my perspective, I don't think there is any direct action you can take to recover what you had. You may simply end up having to view it as a learning opportunity and hope for better outcomes in the future. My best wishes to you...