I know nothing about Massachusetts diving, but Oklahoma has lots of 2 foot vis diving or less....then sometimes it opens up to 20 feet or better. A little planning can eliminate the need for shooting a compass bearing and following it, although you really should know basic NESW orientation.
For shore diving, you can always swim out to a set depth, then keeping the uphill slope on one side, swim for a set time, hit your turn and do it again in reverse. Pick a starting landmark, stack rocks, use a stump, even a beer can if necessary and that's your stop point. This works pretty well for most lakes.
I have seen navigation slates made out of cutting boards (I think) with a compass glued on them. You can write nav notes on the slate as needed. You hold it in front of you and it really improves following a bearing.
If you don't have a Shearwater Perdix yet, go ahead and sell a kidney on Craigslist and get one. The compass allows you to set a bearing marker and the computer will tell you to correct if you get off track. It also marks a 180 degree bearing for the return trip. It pretty sweet....probably not $1300 worth of sweet, it it's an awesome computer all the same. I didn't need that other kidney anyway.
Unless your in the ocean or avoiding boat traffic, who cares if you get lost. Just pop up, get your bearing, shoot a course and dive again. Do y'all have to pull a dive float or set a flag? I tend to swim in a big circle to the left if I'm not following a compass heading or staying at a certain depth. For my fun dives, I'll just go look around with no particular destination in mind. At my turn point, follow the depth back to 15-20 feet and kick around for 3 minutes and pop up to see where the exit point is.
Now all that being said....navigation isn't hard, but it does take practice. A small wrist slate or whatever style you prefer is handy for writing a bearing on. A day in a dive park or lake with some buoys can dial in nav skills. If there is not a dive park, go to your favorite site and set your own.
As far as nervous, if it's the conditions than make you feel in easy such as waves, difficult entry, underwater obstacles, or whatever else, find a better place. You can't get hurt on a dive you don't do. If your worried about getting lost, don't be. Unless your going deep or trying to cover a lot of distance, kick around for 20 minutes, pop up, and do it again.
ON EDIT- When you absolutely, positively, have to get back to where you started...there is this genius device. Used by divers in deep dark places no sane person would go, and lost means dead. Kind of embarrassed I didn't put it in there first.
Dive Rite Classic Primary Reel, 400 ft #24 Orange Line
Good luck!
Jay