Hey.
I too have a generously proportioned boyfriend. Lube was a help for us even before the herpes but it was a life saver after.
It's perfectly understandable to be worried about having sex again; after all, you're in pain right now.
Honestly, for me, I did have some problems the first few times (but everyone's different). I had had a very bad first outbreak. Even the doctor winced when she examined me. One big sore was right on the entrance to my vagina and this damaged the skin there, leaving it weak. When I had sex again, it was a bit painful in that spot, but changing positions alleviated the pressure. I went back to the doctor, paranoid that I was having another outbreak. She said she could see why I thought that, but it was just a split in the skin from the friction because it was weakened. She gave me a natural cream called Mebo to put on it to help it heal. It smelled like marmite but did the job! I had to give myself more time to heal but things are fine now.
Our sex life is a little different now (he doesn't have herpes and I want to keep it that way!) as we have to be more careful, but no pain, and he doesn't have to go easy on me! You can have a fun and fulfilling sex life again, but give yourself time. DrSuz is right, you might have to start gentle and work your way back up, both for the benefit of your body and your mind.
I don't find that sex is a trigger for episodes. I started off having them every month, they always came a few days before my period. I tell you, just the thought of having a tampon inside me was scary after my first outbreak, let alone a cock! They are less frequent now. Haven't had one since November, I think.
I apologise for the over-long post. I wanted to let you know that it is normal to be worried. It doesn't have to ruin your sex life unless you let it. Sex might trigger outbreaks for you, but it might not. And if it does, you'll learn to manage it, just like Katie.
Love and hugs
Xx