I completely understand you! The darker the place i'm in - the more creative i get. But yeah - from time to time life wants to mess with me and i feel happy - it helps when eventually everything goes back to hell and i have a burst of new and fresh ideas - but the dry points are sometimes killing me. What works for me is books. I suggest you check out (kinda doubt that you haven't tho) H.P. Lovecraft. He writes some dark and depressing stuff that always inspire me when i need to go in a bad place. Here is a shot from when i was in a fresh relationship and was happy af, but still managed to pull this out of me with almost nothing.
But tbh i have found out that some down time and recharge is good for you! Allow yourself to feel and express the happiness in your shots. Discover some different aspects of your art and maybe you will find something new or a good way to combine them. Take some colorful happy-ass portraits and let us see the outcome.