Hey Brian. I think your situation is similar to what most banjo players experience at some point. I can only tell you what has worked for me over the years. Others will have their own suggestions which will certainly be worth considering.
Anchor fingers: I would suggest trying to plant two fingers on the drum-head, but if you can’t, many people do very well with only the pinky down. When I was an early beginner, I too, planted only my pinky, I also played with a very tense hand as I was often trying to go for Speed; a common pitfall of beginning banjo players… My right hand would actually become tired during practice and I would push my anchor fingers around the head which destroyed my accuracy and speed. You mentioned glue, well confession-time: I tried that too by using glue-stick on my drumhead to keep my anchor fingers from getting pushed around, but I found out quickly that my anchor fingers were getting pushed around because I was tensing-up my right hand way too much. It took me about a month of slowing down and rubber-bands tying my ring/pinky together to get both fingers down without thinking about it. I feel that it almost doubled my right-hand stability and helped my picking accuracy.
As for your hand-position rolling-back, might I suggest Banjo Ben’s “Foggy Mountain Lick” lesson? Other lessons might work, but the Foggy Mountain Roll is very easy to memorize and thus, you can spend time observing your right-hand position. You will find that you will have a certain maximum-speed without losing your correct hand position or before you start pushing around your anchor fingers. You might call this a Speed-Limit for now. Perform a one or two measure ‘loop’ so you can observe your right hand behavior while doing this. Do not exceed your speed-limit by sacrificing accuracy! Practice with a metronome and see what your speed limit is, and then use that as a reference, demanding proper right hand position and technique. Another trick I use, is to put headphones on and listen to a radio-show while picking that lick over and over demanding perfect right hand posture and relaxation. Try not to get too impatient, as the speed will come, and when it does, you will have the accuracy that comes along with it that will make you stand out as a banjo player. Good luck and HAPPY PICKING!
PS: It might help to submit a short video of your right hand position for maybe Banjo Ben to analyze. I am not an Instructor so I hesitant to make suggestions on hand-form or wrist arch etc… I only know, it’s not a good thing to rest your palm on the bridge, unless you really don’t have a banjo mute!