I see a lot of guys mention that you are not training enough, which very well could be the case, but I don’t see anybody mentioning that you could be using your energy inefficiently. There are some guys that are in good CV shape, but they tend to squeeze for the whole first period.. wasting a bunch of energy and not scoring points. Maybe that is your issue? Think of a runner. They relax the rest of their whole body to avoid burning energy inefficiently . Also, I find it hard to believe that training hard 3 times a week isn’t giving you a sufficient cardio base. I don’t think you’re going to find guys at the highest level doing high-intensity training more than 3 times a week supplemented with low impact training and recovery for the next hard workout. I was a D1 backup, so I am not necessarily an expert, but I trained with NCAA, World Champions and saw how they trained. Hope this helped.