I quitted smoking 4 months ago and have been going to the gym since.

In these 4 months, I have gained 4.5kg.
My gym days are Tuesday, Thursday and Saturday and I have been doing the same exercise for every session. These are my exercise
(Set/Rep)
Dumbbell Bench Press (5/8)
Dumbbell Shoulder Press (3/8)
Barbell Curl (5/6)
Cable Front Pull Down (3/10)
Barbell Bent Over Row (3/12)
Barbell Upright Row (3/10)
Barbell Pullover (3/8)
Cable Pushdown (3/10)
*** not in order ***

I start with Dumbbell Bench Press first and the exercises for my arms are usually last. It will take me max 57 mins for me to finish a session.

I am just wondering if I am over-training or can my program be ‘fine-tuned’? I don’t do my legs because I have damage my right knee ligaments.

There hasn’t been any visible growth or significant improvement recently and I am worried I am hitting the plateau.

Please advise.