Hill sprints. Do them twice a week at first. One of the times allow yourself to recover fully between each sprint. That will build lower body explosiveness (ALL striking power originates in the lower body). The other time you do them don't allow yourself to completely recover. Do a set number of hill sprints, enough to really push you hard, and time yourself. Next week try to do the same number in less time.
As for your diet, you need to maintain a balanced diet. No crazy bodybuilding ketogenic fat loss diets. You need enough protein to support recovery, enough carbs to support your frequent training and enough fats to support hormone production and mental health, so keep it balanced and use calorie manipulation to create slow and steady weight loss.
Too many martial artists try to use resistance training to build conditioning, and end up neglecting maximal strength. Use your weight sessions to get brutally strong. I developed scary hard punching and kicking ability through building pure maximal strength and spending plenty of time on the heavy bag.
Add in steady state cardio once a week, either jogging or a cardio machine for a good 20 minutes or so.