I could use some assistance in helping my boyfriend reconnect with his affectionate side.

I've been in a relationship with my partner for over four years, following three years of an on-and-off dating period. We made the decision to fully commit to each other, introduced our families, and even talked about getting married in the near future. For a long time, he felt like my best friend, and I believed I was his as well. Like any couple, we've had our share of minor disagreements, but nothing significant—until recently. Lately, I've noticed a shift in our dynamic, and I'm struggling to understand what's going on. A recurring issue relates to his friends. I've often felt that they take their jokes too far, making me uncomfortable. He brushed it off and said they meant no harm. However, during a trip with them a few months ago, one of his friends called me "difficult." I don't see myself that way—maybe I'm just not the typical "submissive" person. His silence in that moment really hurt me. After returning from the trip, I expressed my concern to him: if he couldn't defend me in front of his friends, how could I expect him to support me with extended family in a similar situation? (Just to clarify, I have a good rapport with his immediate family; my worries were primarily about the extended members.) Since that conversation, he's become emotionally unavailable. When I ask him what's wrong, he shifts to different issues: first, he didn't want me distancing myself from his friends; then he cited our families being too different; he has mentioned struggling with depression; and ultimately, he’s claimed that I’m the source of his unhappiness. He talks about how we are too different and even brings up past conflicts, saying they weigh too heavily on our relationship. I’ll admit that I wasn't easy to deal with at the start, as I wasn't ready for commitment back then. But that was long ago, and we had moved forward. This sudden change is bewildering to me. For over four years, we've genuinely enjoyed our time together and navigated our differences. How does someone just switch like that? I've been doing my best to restore what we once had, and there were moments when it seemed like he was starting to come around. However, whenever I express a desire for mutual effort, he pulls away and claims he doesn’t think we’re working anymore. It seems like whenever I try to delve deeper, he becomes uncomfortable, and then he tells me he feels unloved, even though he's not allowing me to show him love. I recognize that at the beginning, I made things difficult for him because of my reluctance to commit, and I hurt him during that time. He forgave me, though, and I thought we had moved beyond that. How can he now use that as a reason to consider leaving? I suspect he might be going through a depressive episode and is projecting his feelings onto our relationship, which is an aspect of his life he can control. However, when I brought this up, he dismissed it and insisted that I’m the reason for his unhappiness. For context, he's more introverted and non-confrontational while I'm the opposite; I prefer to discuss and sort through issues. Being in this situation where I feel I have to tiptoe around him is incredibly frustrating. I acknowledge that he used to handle much of the emotional work in our relationship. He has been an amazing boyfriend and more than I ever could have asked for, and I might have taken that for granted, assuming we would always be together. But I’ve been actively working to improve that dynamic. He is my person, and I genuinely want to make this work. However, he's now resurfacing past grievances and using old reasons as excuses, leaving me confused. I'm committed to finding a resolution and supporting him because I know he’s a wonderful person, but I need some reassurance from him as well. He often claims that things are getting better when I bring up the subject, yet whenever I express concerns about reciprocity, he suggests we should break up (which is where we currently stand). How do I remind him of what we have together? Why has this change occurred? Any advice would be appreciated. How can we reach such a turning point after everything we've been through together?