I was in a situation a lot like yours recently. The thing that kept me sane (and I mean that only half figuratively) was my bike. Don't ask me to explain it, but everything else would just melt away while I tooled around the city in the middle of the night. I don't think bike riding is some mental cure-all. I just think you need to find what works for you. Maybe it is bike riding - or maybe painting - or music - or writing, jogging, the outdoors, spirituality, volunteering, juggling, cooking, dancing, reading, teaching, or something else entirely. Stick with that something.
Oh, and I like the bike=]