Is it wrong for me to change churches?
No, you can change churches for whatever reason you like, and as often as you like.
Having said that, I agree with some of the others who have commented, that the awkward situation between you and your friend really shouldn’t affect your experience of Mass at all. You have acknowledged this somewhat, but it seems to me you do still cherish some wish to restore the “togetherness” feeling that you were used to prior to your falling out with your friend. But really, Mass isn’t about togetherness with the others in the pews. Many Catholics think that it is, of course, but this is a serious misunderstanding. For you to have lost your primary point of social contact during Mass is undoubtedly painful, but it may in fact be an experience you needed in order to force you to put your focus
fully on communing with Christ. In other words, you should separate your experience of Mass
entirely from any social concerns or needs. Deal with them completely separate from Mass.
There’s another thing that hasn’t come up yet in this thread. It’s possible that your friend is justified in cutting you off. You haven’t explained in any detail what the initial discussion between you and him was about, so I can’t be sure, but I’m guessing what happened could be something like this: Up until recently your friend probably considered you a reliable sister in the Faith, and during the discussion you said something that made it necessary for him to reassess that. From your friend’s perspective, this suddenly makes you a
totally different person for him. Do you understand that? Me personally, if a long-standing friend of mine whom over the years had given me the feeling that he was a strong believer, suddenly started talking to me as if he doubted God, I would react similarly to the way your friend has reacted. It cannot be any other way, because a friendship with a faithful believer, as compared to interaction with a doubter or skeptic, are radically different things. You cannot expect to go from being a believer to a doubter and have your relations with strong believers remain the same. This may sound harsh, but I’m just pointing it out as something you might want to think about if you plan to make any attempts to mend things, and also so that you may ask yourself the question if it’s really him who needs forgiveness…