Regarding your supplementary resistance training, something which people often overlook (even very highly skilled boxers or boxing coaches) is the need to maintain structural and muscular balance (especially at the shoulder joint as it is the most mobile/least stable joint in the body and takes a lot of punishment while boxing).
The act of boxing itself places a very, very high volume of partial ROM shoulder flexion, shoulder Horizontal adduction, and shoulder internal rotation on the musculature of the Glenohumeral joint (shoulder) and generally a lot of protraction and elevation of the scapula along with it. If not balanced out, or worse yet exacerbated by piling on yet even more strength work which works these same movement patterns, the likelihood of shoulder problems becomes very high.
To balance this out you must include shoulder extension work (which you have practically none of with the exception of pull/chin-ups which do not adequately maintain proper ROM into shoulder extension/arms behind the body), External Rotation work (which you have some of, but I'd like to see more), and upper back work (specifically lower Traps and Rhomboids).
I personally would recommend doing only 1 Upper Body pressing movement (and would prefer higher reps, in the 12-15 rep range) and would choose either a fully contracted should pressing movement (overhead dumbbell press, headstand/handstand push-ups, etc...making certain to achieve full shoulder flexion at the top of the movement) or a fully stretched shoulder pressing movement (parallel bar/dip station dips, Dip Machine, Single bar dips, Korean dips, etc...attempting to build as much strength and ROM [though not necessarily at the same time] in the fully extended should position). I'm not necessarily against doing things like Bench Press (Barbell, Dumbbell, Bamboo bar, etc...) or Push-Ups (traditional, narrow, pseudo planche, etc...) variations mind you, those can be good builders of basic strength, but again, you are already doing a ton of strength endurance work in that movement plane; better to strengthen the portions of the ROM you aren't hitting while doing your strength work.
The rest of your Upper body strength work should be focused on working the muscles and movement patterns needed to balance out your shoulders. Things like:
-Weighted Shoulder Extensions, Reverse Plank, Table Holds/lifts, Crab walks or AG Walks to strengthen your shoulder extensors
-Face Pulls, Scarecrows, Wall Slides/Extensions, or "high" cable external rotations to strengthen your external rotators and upper back
-Prone barbell front raise (you can do these seated and leaning forwards or with your chest on an incline bench to begin with and then progress to laying on your stomach on the floor or a flat bench), dumbbell Y raise (same progression as above is fine), or weighted Dislocates (assuming your can easily reach full shoulder flexion with a weighted bar, you also should start with a light bar and wide grip on these and then progressively work your hands in till you are shoulders width, then add weight and repeat) to build the lower traps, and help maintain full ROM into flexion.
-rows variation (barbell, dumbbell, TRX/Ring rows), pull-up/chin-up variation (narrow grip, wide grip, behind the neck, L-sit variations), muscle-up variations (only recommend controlled/slow variations especially through the transition), or rope climb variations.
I think your lower body work generally looks ok, but if you are having trouble with your lower back you may want to go back and make sure you actually have the mobility and joint preparation necessary to make loaded squats/pulls a necessary progression to build strength.
Finally you have zero core strengthening exercises. I would strongly suggest fixing that.
Good luck and hope this helps.