Night time is so isolating isn't it - and I imagine much harder when you know you have to do it alone.
Sounds very much like he's hit that natural developmental stage with is often called "sleep regression". At this point their brains change how they fall asleep and stay asleep, and for a while you get a baby who seems to wake all the time, never seem deep asleep etc. I ended up holding our LO through her first few sleep cycles every night for about two weeks (so for about the first three hours 7pm to 10pm) and we could see her twitching and squirming like her brain was wired. After being soothed quickly back to sleep a few times (because she was already in our arms) without needing to wake fully to get our attention, she seemed to calm down and sleep a bit deeper - so from there we put her in her basket and it was then easier to get 3 hours before she then woke for a night feed and went down for another 3hrs. After a few weeks we noticed she wasn't so jumpy in our arms and seemed more settled so we tried holding her for less and less time before putting her in her basket and thankfully it worked.
I know breastfeeding can be challenging because it feels like its all down to you and you'll never get your body back or be alone, but it isn't forever; feeds will space out, he will grow up and need you less. As you've already discovered breastfeeding offers your baby more than just milk, its the comfort that gets him back to sleep and makes your life easier during times when he's feeling unsafe or overwhelmed. It's a way of mothering, not just a way of feeding, so whether he needs the milk or not he may well still need the breastfeed. Him using you for comfort is his natural biological instinct and while it can make us feel overwhelmed as mothers sometimes, it's not wrong for your baby to seek this comfort or for you to give it if it feels right, and easy, to do so.
Do you have any support you can call on during the day to allow you to get more rest if you know you will be up all night. Even a couple of days of someone around to support you and give you a bit of respite.
If you feel comfortable with the idea, maybe look in to safe co-sleeping to see if you are able to make that work. Even people who don't plan to co-sleep find they do so occasionally when they just HAVE to and its much better to know in advance how to do this safely than to do it accidentally in an unsafe way.