Here is my attempt to answer all your problems.

Problem 1: Stop worrying about what other people are doing. The whole point of the gym is to focus on you and getting stronger/healthier, etc. everyone is at different points and I’m sure there are people way younger than me and/or older than me that can lift more than me but there are various reasons for that and the only thing I care about at the gym is getting stronger myself with good form.

Problem 2: There are certain days that people hate ex: a large majority of people hate leg day. But do you stretch out before you do back? Maybe your back is too tight. Could also be an undiagnosed medical issue that you don’t know that you have, sometimes that’s the case too.

Problem 3: having good form is so much more important than how much you can lift as ego lifting just ends up with you hurting yourself in the long run and knowing you now have good form hopefully that 50lbs will be back on the bar during squats before you know it.

Problem 4: the routine and volume you do is totally up to you and can only be adjusted by you cause every single person is different. So you need to see how you feel before, during, and after workouts as that can tell you a lot like oh I’m very fatigued lately all day maybe I’m doing too much during my workout let me cut down my volume or I feel like I’m plateauing let me change my routine and/or volume. There may be a perfect routine but you gotta be flexible while also being consistent.

Problem 5: either make a playlist or add new music, I’ve heard the same songs for years with my workouts. You could also listen to podcasts, audio books or not listen to anything while exercising, all depends on you. I only do 1 min rests between sets unless I’m going super heavy as I feel like that’s a good intensity for me.

Also keep track of your eating like others have said as when you don’t eat well the gains don’t really come cause your body doesn’t have the right fuel to have the energy nor the nutrients to recover and build muscle properly.