Need some advice!

So I never breast fed my baby. Deep down I felt so guilty that I didn’t. So recently he turned 6 weeks old and he has been constipated for a bit so when I went to my WIC appointment I asked them if I’m still capable of breast feeding and we went through the whole thing and now I’ve been trying to pump and give him my breast each feeding . But I noticed that he is no longer constipated now that he is getting a little bit of my milk each day, his poop has turned somewhat seedy and yellow again which I’m glad, but he has been fussy and gassy and I’m guessing it’s from the fenugreek I’m taking. Is my milk really working for his stomach? My nipples are so sore I almost want to give up😢 but with the way he is finally pooping i really don’t want to. I really want to be able to give him what he needs but the pain is sometimes hard to hold in while he feeds from me😭