How about saving one evening a week as a 'you and him night' - getting dressed up, going for dinner, or watching a movie anything where youre spending quality time together instead of just time together. It sounds a bit odd saying spend more time with him, but if you designate an evening, say a thursday and stick to it, it might help to relax you when he has his nights out without you. Then you can do your own thing on those nights he isnt in and now and again come back later than him so you dont feel like youre the one always waiting for him to get in

Youre not a mental case at all, you just love your boyfriend very much!