BF trouble - 7 week old

My baby is turning 7 weeks old on Wednesday and we are still struggling (50% of the time) to breastfeed. I thought by now he would have the hang of it. Sometimes he does fine and has a great feed but other times he’s frustrated and just continuously unlatches I’ve been trying everything the lactation consultant told us to do and it’s really just hit and miss whether or not he eats well. I have no idea what’s going on or what I could be doing wrong. Is anyone else still having trouble or have experienced this before? Did you try anything different that seemed to work? Or do I just need to give him more time to get the hang of it?? Advice and opinions please!