I've been latching my son since birth and also encounter this problem from 3 months onwards (now coming to 4 months). It first started with him being very distractable, keep latching on and off during feed to look around and also impatient if slow let-down. Then suddenly, he refused to latch on, will cry and arch his back whenever I put him to the breasts even though he's hungry. I made a mistake of forcing him, and he got hysterical. Hubby had to calm him down till he's drowsy then he'll latch on. Dreamfeeds no problem coz he's drowsy.
He also went on milk strike for a few days. Was super stressed for that one week coz felt so dejected and worried he didn't drink enough. My milk supply dropped and had to ask mother in law over to help for 2 days to give bottle EBM. I dont't want to give bottle coz I want him to know mummy as only breastfeeding.
Read up on kellymom and suspect it could be nursing strike. Also brought him to see doctor coz he got blocked nose (one of the reason why he refused to suckle).
I'm now taking baby steps to get him to accept me, offering my breasts anytime he seems to be keen and using some of the tips on kellymom. Currently, the method that works is to rock/calm him till drowsy then he will latch on. If daytime he takes very little feeds, will make it up during night feeds (2-3 feeds, no choice have to endure). Hopefully, he'll pass this phase soon.
You might want to read the articles and tips on kellymom and see if they work for you.