I agree with PP - DON'T GIVE UP!
I had a very similar situation as you - pumping got exhausting, I was over it. DS is 20 weeks now and he's EBF with a bottle here in there if I go out. I've pumped maybe 5 times since October.
When DS left the NICU we were doing every other feeding at breast. Over the next month and a half we transitioned from that to full breast, switching a bottle for boob every week or so.
As for the nipple shield, after much work we were able to ditch that right around his EDD. One day it just finally clicked.
You can do it. It's so worth it. Don't give up!