How long should a workout actually be? Mine are hitting 2 hours

You have 28 sets for chest, shoulders and triceps in one session, then you do it again 3 days later. That is 56 sets a week for those muscles. The research on volume says the benefit flattens out around 15-20 hard sets per muscle per week and you are way past it.

Cut to: bench 3, incline DB 3, OHP 3, lateral raise 3, one tricep movement 3. 15 sets. Rest 2-3 min on the big ones, 90s on the small ones. That is 60-70 minutes and your second half will stop collapsing because there is no second half.

The sets you cut were not doing anything. They were just making you tired for the next session.

Also 6 days a week is a lot for most people with a job and a girlfriend. PPL 6x is a bodybuilder schedule. PPL 3x with the leftover 3 days for walking will probably get you the same results and a relationship.

Time your rests. I bet half of your 2 hours is phone. When I actually timed mine I was resting 4-5 minutes between lateral raise sets without realising.

Supersets for the small stuff. Lateral raises paired with tricep pushdowns, no rest between, 90s after the pair. Cuts 15 minutes off a session with zero downside.