What would you suggest to help me lose lower belly fat without losing butt?

No guarantees that: You won't lose butt fat. There is no such thing as spot fat loss. You would need to lose weight in general & a certain proportion of that will be abdominal fat. This can be done by eating healthfully, being physically active and making sure that calories burned exceed calories consumed.However you can improve your appearance by toning your abs. To tighten your abdominal muscles consider doing.