I found stopping gradually worked, so started by telling ds I would only feed him upstairs, so it broke the habit of feeding on the sofa whenever I happened to sit down.
It seems like a palaver, but after a few times of doing this, when I reminded him it had to be upstairs, he sometimes would decide not to bother. I made feeding upstairs pretty dull, no stories except for at bedtime, and away from the tv. This resulted naturally in him asking for feeds less, but I never actually had to say no to him, so he wasn't upset by it.
Then once that was established, I would only feed him in his bed, never mine.
Then we were down to nap time and bedtime. We either dropped nap altogether or moved nap to car/buggy.
For bedtime I introduced a milk beaker that I let him choose (with robots on) and said it was special milk for bedtime, then I stopped feeding him in his bed and would instead offer him a breastfeed while sitting on the floor of his room (so he couldn't get too comfortable!), then he had to get into bed for stories and special (warm, cow's) milk.
Within a week of this routine he fed for shorter and shorter periods, then would forget to ask sometimes, then went longer without asking, then stopped asking.
It was still hard and sad but made easier by the fact I never actually had to say no, I just sort of encouraged him to give it up by himself, and he wasn't at all distressed by it in the end, despite it being so important to him and I feel really proud of how we managed it. He was 2 and a half.
You would obviously have to adapt for your own situation, but hope something there helps. Good luck!