Nursing, should I just stop or how to keep going?!

Ami
Okay so my baby is 10 weeks old, he solely breastfed until 5 weeks only gained about 8oz my pediatrician told me I needed to start supplementing. Well as this began the less and less my son would nurse... Now we are to the point he basically won't latch at all anymore, and when I try to pump I get less than an oz total from both breasts. I just don't know what to do, I know how beneficial it is to my baby, but I just don't know what to do to produce more, I have been taking fenugreek since he was 4 days old, eating oatmeal cookies rather often, drinking a great amount of water, and we have a good sleep schedule. At this point I just don't know what to do, I am open to any helpful advice as to how to get him to relatch and upping my supply, or if I should just stop. (Side note with my first he never latched and I pumped for 6 weeks, I always had to supplement with him, and I just never produced enough)