I can really relate to your situation OP. I breastfed my small person til 3.5 (I didn't set out to do so...it just sort of happened).
I assumed he'd just grow out of it eventually or just give up naturally. He didn't. I started to wonder (and then worry) how we were ever going to stop. I started to get a bit of breastfeeding aversion. Sometimes quite severe episodes - not very nice for either of us.
I made a conscious decision to stop feeding during the night (which had to that point been my default way of getting him back to sleep every time he woke...which he did....a lot). I just stopped the overnight feeds. I would still go into his room every time he woke, but instead of picking him up and automatically giving a feed, I found I could soothe him back to sleep by rubbing his back. "Wow", I thought!
So we were down to one feed first thing, and one feed last thing before bed. The morning one was next to go - we organised ourselves so that my DH went into him when he woke up in the morning, and when DS wanted / expected a breastfed he was fairly easily distracted. He'd normally have some cows milk. "WOW", I thought!
The bedtime feed to sleep was the last to go. We took the plunge cold turkey style on this one - I booked 3 nights away (locally, as still wanted to be around during the days). It went surprisingly well and although I think there were a few tears on night one, that was pretty much it.
The end of an era? Yes, of course
Any regrets? None
Did my boobs adjust OK? Yep, fine. Didn't need to pump once
Did I feel a bit sad after giving up? No. I thought I would but I didn't
While I appreciate that not everyone can / wants to / is in a position to breastfeed for so long, weirdly I think that stopping at 3 was much easier than it would have been when he was smaller. I'd talked to him a lot about my plan to stop - "Mummy's almost run out of milk now! You're such a big boy now! When Mummy goes to stay in her hotel and comes back you'll get lots of cuddles but no more milk!" and I think setting expectations really helped.
Sorry for the long rambling post but I hope it's in some way helpful. Good luck!