I had the exact same problem with DS. The first 3 weeks were horrendous for me. My advice is either the same as what you've been given or is what you're already doing so while I have no words of wisdom, I just wanted you to know it's common, you're not doing anything wrong and if you end up comp feeding, then so be it. You can always go back to full time BFing later on. I basically did block feeding, lots of lansinoh, walked around with my boobs hanging out (classy.....and there wasn't even alcohol involved!) and fed in the football hold. The change in hold was the biggest help to me. They do heal quickly though and I kid you not, the improvement once they healed was almost instantaneous.
And remember to relax before a feed. Being anxious makes it worse. Whip out the old CalmBirth techniques