Hi,
I have had a real problem with BF my daughter too (but she is still EBF and she is 10 months).
I have a couple of questions, are you feeding him solids yet, can it be that you are crowding out BF with FF and solids? May be you could reduce those to see if he is more eager to see BF.
if you are confident the answer is no to the first question, the the next question I would have, is it possible that he is super efficient with BF? My daughter once suddenly reduced her time on breast and that was her new time to empty the breast. ( I was very stressed until I figured out that one ).
Now, if neither is an answer to your troubles, I would guess it is something we went through too, restlessness probably it was, I really can't say. So what I did is change positions where she would finally be willing to suck for longer. For us the usual sitting position DIDNT work at all for few weeks,so I lay with her side-to-side. There are so many positions you can invent for him to feel at ease, but something might work. I had to pretend I didn't care too, I would sing to her our calm song but the breast was nearby, I would talk about something, until eventually she would just decide to suck some.
I would say one thing most important, persevere if you want to BF, it's good for his health too, but try to avoid making it more stressful for both (easier said than done, but try not to panic). I was panicking myself, especially since I didn't want to FF at all, and I think she sensed it. But please please remember it passes, just gently keep doing what you think is best.
Ah, also can you somehow work on offering less at night, that can certainly carry into less appetite for the day. I never cut night completely, as some advised, but may be just a little bit less night feeds you could try? FF is so easy, so BF may be just too much extra work for him? I will try to recall what else worked for us and will post again, it was trying times, I know how you feel!