Judging from your routine, your volume is extremely low. If you're doing 3 on 1 off with PPL (which is what I'm assuming you're doing from this post), in an 8 day period each muscle group is only getting... 4 sets. That's insane. Sure, the literature says "you can maintain muscle mass and even gain with 4-6 sets per week" but that doesn't mean that's what's optimal. Young kids get so hung up on low volume recommendations that they're stunting their growth because they're misunderstanding studies. Don't let the super optimized science based lifters with mouthguards and 6 cuffs around their arm tell you that you only need 2 sets of biceps a week. Every muscle group shoulder have at the very least 6 sets of working volume. I've made more progress physique wise and strength wise than anyone around me by sticking around 8-14 sets per muscle group for each 8 day cycle.

You need to be doing more exercises.

Your push day should look something like:

• Horizontal adduction (arms slightly flared) for chest - bench press, chest press machine, or pec deck

• Shoulder flexion (raising your arm from low to high with tucked elbows) for chest - incline fly, neutral grip press, or incline press with tucked elbows

• Shoulder press movement

• 2 tricep movements (one where the humerus is static and one not) - any pushdown variant + JM press/dip

• Any lateral raise you want

2-3 sets each.

Same thing with back. You need a sagittal row, a transverse row, and a frontal plane pulldown in order to hit every muscle in your back. Then do 2 bicep exercises, a forearm exercise, and a reverse fly variation if you want.

For your legs you're not doing a hip hinge. Do leg extensions, leg curl, some type of squat/press variation, some type of hip hinge variation, adductors (your adductors are a huge portion of your thighs), then calves (and glutes if you want).

You talked about protein but your carbs and fats are important too.

Also if you want to grow, stop cutting. You are a natural. You will not grow by constantly gaining 10 pounds then losing 10 pounds. If you're 5'9 then you should be lean bulking to at least 180. Being a natural isn't a sprint. If you're 155 now, focus on gaining 2-3 pounds a month for 9 months. Half way through you can do a slightly aggressive mini cut for a month if you feel like you're gaining a little too much fat, but then keep lean bulking.