I'm at work hun, so have to be quick, but wanted to say it sounds like you're doing an amazing job! I also needed to use nipple shields for the first 12 weeks or so of BF so totally get what a PITA they can be!

But one tip my LC gave me which turned out to make life much easier was to hand express a few droplets of milk around the edge of the shield before you start. Doing this makes it much, much easier to keep the shield in place because the moisture holds it there iykwim. It also means it's less work for bubs to get a let down (which a shield can make a bit more difficult) and they can smell the milk so are more inclined to attach without the battle.

Hope this helps, hang in there, I know it's hard to believe at this point it time but it will get easier... It just happens very slowly, but in 6 weeks you'll be looking back and think OMG how far have we come. GL