Attention experienced breastfeeding moms

So I'm a mom of 2, with my 1st child I only breastfed for 2 weeks then pumped and gave bottle up until she was 5 months because my milk dried out but around 3 months I started giving her more formula than milk because I didn't produce much. And honestly I had no interest in breast feeding, I hated it. But since then i've changed my mind about it and 

I now have a 3 month old son who will be 4 months in 2 weeks which I had breast fed , and now i'm facing a problem . 

So for the past 3 months he's been exclusively breast fed I never gave him a bottle or formula because this time around I produce a good amount of milk okay so as of 4 days he all of a sudden screamed and cried at the top of his lungs when I turned him to his side to breast feed him (thats how I always breast feed him on his side laying down) I kept trying to latch him and he would just turn back on his back and keep crying I felt as if his side hurt so I turned him to the other side but still he refused. I then pumped and gave him a bottle and he took it and thats what hes been drinking from but every time hes hungry I try to latch him with no luck. I tried breastfeeding standing up as well as sitting in a chair and other types of breast feeding positions but he wont latch any way. It honestly makes me so sad because I miss nursing him I miss that bond we had, i read online and it said hes on a "nursing strike" and it listed reasons why the only one I related to is that i've been leaving him a lot with someone else (my mom) which makes sense because I started letting my mom take care of him around the same exact time he refused to nurse but as of yesterday I stopped giving him to her but he still has no interest in latching :( does anyone know why this is happening ? And does anyone have any tips on how to get him to latch again ? Will a nipple shield work ? Idk what else to do my MIL suggested to let him cry and said if hes hungry he will latch on but I've tried that and he still refused plus I feel bad for letting him cry. 

I wanted to nurse him for at least a year this makes me feel like a failure I was actually proud of myself for breastfeeding this long. Its also harder because before he would nurse and fall right to sleep now its harder for me to get him to sleep, he doesnt seem like hes sick or anything so idk why the sudden change there has been no changes with me and my routines