Hi, OP here. Just one final update in case any newbies find this thread down the road. (Sometimes I Google and find archived SB threads from years ago that really help if the OP has updated. Last one, promise!)
I have kept diving since this post and we just got back from an amazing diving vacation in Grand Cayman. It's funny to read back on this thread now even though it was only a few months ago because things just naturally improved as we kept diving. Our buddy communication is seamless now and we do have more signals, but a lot of the time we just use universal short symbols to piece things together under the water. I found that this really helped when we went on boat dives with DMs in Grand Cayman as well because obviously they've never dived with us and if we had some "special" signal for everything, it would be hard to communicate with other divers and the DMs. I've never had an urge to surface again like I did on one of the first dives that prompted this thread; I'm not sure what to attribute that to other than:
(1) we go over dive plans now before getting in the water,
(2) I'm more comfortable under the water and confident in my abilities just from diving over and over again,
(3) I don't rush myself and I don't beat myself up over mistakes anymore, like accidentally kicking up a little sand around much more experienced divers (although we have really been working on buoyancy and I try not to!), and
(4) if worst comes to worst and we're trying to communicate something that the other one isn't getting, we just shrug and signal never mind and enjoy the rest of the dive (assuming the communication isn't urgent, obviously).
In short I have found that diving is a great cure for perfectionism and have learned to just enjoy myself while continually improving

. I haven't had a truly bad dive since this one but I have had ones where I was too tired, too cold, a little uncomfortable (exploring the entrance to a cave - not really for me, the darkness felt too ominous to me and I had to think happy thoughts and not look into the dark unknown too much lol), or just plain not feeling it, and that's okay because the good dives far outweigh those and I find that there's almost always something small to get out of even a crappy dive. So if any new divers are feeling discouraged or like everyone else is getting it and you're not, please keep diving! I don't think any amount of practice above the water - skills, communication, whatever - helps as much as experience under the water.