Never have shot a peep. Joke with my buddies that peeps are for pu**ies! :fit: But seriously, I respect each archer for striving to be as accurate as possible. If a peep is necessary, great. In fact, I am the only guy in my group that doesn't shoot a peep.
Sounds like the peep is an issue for you and may lead to poorer accuracy???
Muscle memory is the key. Practice becomes important to retain that memory, I shoot a little bit year round (seldom go a week without slinging 25 arrows or so) and really shoot a bunch August through January (25 to 50 arrows every day I can).
I have four or five spots with my anchor that tell me I am "there". String on nose, thumb below jaw, top of hand on ear lobe and release in the corner of mouth. All of that puts the valley between my thumb and pointer finger solidly on the back of my jawbone, kinda like a perfect fit. These "feel" zones act as a check point and become second nature, in fact, I don't even think about it unless my accuracy is suffering. Something else to consider is your bow arm. For me, it is a feel and "sight picture" thing. A muscle memory thing that I can't even describe in writing. A bow torqued differently from shot to shot will throw things off.
Also, there are accessories that can be placed on your sight that help with proper alignment, both anchor and bow arm. Look up the "No Peep", and the IQ line of sights (I think) offer a visual clue as to alignment...again it becomes second nature and muscle memory takes over after a while. I hear after you shoot with them, you get where you only look at it when accuracy is off at the range.
Finally, with the shooting up/down angles (tree or steep terrain), just bend at the waist. Keep your back arm in line with your arrow, by bending at the waist and everything will stay in line. If you have practiced enough, muscle memory takes over there too and you know when you have moved your anchor....
Good luck with it. If you can make it work, I believe you will wish you would never have shot a peep at all.