Yeah, you need to lose weight (don't we all); best of luck with that.
Your kilt probably has a second, lower strap & buckle on your right hip; leave a lot of slack in it. It does nothing to hold your kilt up, and it's probably too tight.
I know you've probably been told to wear your sporran a hand's breadth beneath the belt, but bring it up higher so it doesn't accentuate and contribute to that "feature".

I'll have you know that I have the body of a god....Buddha