Mate im an over thinker in many ways so i can sympathise with you. It must get so frustrating if you cant just engage something and grind away at it with taking it appart bit by bit.. Not great for this game in as much as its generally a slow process, even with the best plan it wont happen over night and you need to give things time. That said you will ultimately find exactly what works best for you i imagine and as much as somethings are clearly good for everyone we are all different in someways so whats great for me might not be good for you... Try and yeah, i can imagine thats easier to say than do but dont get too tied up in the details and just push your hardest at each session where you need to and if a weight gets you to 8 reps and not a single one more then great, but if you can take it to say 15 ... also great but next time add a little weight and aim for 15 again, if you get 12 thats your target for next time... kind of thing. Try to look for progression in reps and when that comes add a little weight and start again. I work in various rep ranges of 25 and down to 8ish depending on muscle group etc... Just aim for a constant progression, you wont get it every session but if you push for it youll keep gradually improving over time.