I don't have the visual compliment to see detail in your delivery, but I do notice that you don't stay with the pitch longer after your release. In other words, you seem to bail out of your final move - release then stand up.
A common problem with not only velocity, but location can be an issue when you don't complete the entire choreography of your pitching motion.
Also, as you fatigue, your body is trying to tell you what muscles are feeling tired and what muscles are feeling strained. By staying down more, with kind of a pause, your sense of what's going on ... legs, lower core, back, shoulders and so forth will be more evident - this allowing for adjustments by other parts of your body. Also, this "standing up" move sometimes resembles a shotgun impact on the shoulders and lumbar - not good.
You mentioned the CAN-AM league. This is a grinder of a profession, so keep very healthy, pace yourself, and don't be thrown under the bus just to get some game time. The CAN-AM is very competitive within your own ranks and can isolate a man quickly.
Best wishes with your career.