The fact that you are GAY shouldn't make you ineligible for Christian ministry positions, only if you are not living a celibate lifestyle - the same test that should be applied to any single person in such positions. I'm disappointed to hear that you are stuck with a church environment that is so ignorant - but perhaps my own very positive experience on this issue makes me over optimistic about others' environments. And I guess the fact that you have a YF would be compromised if you were known as gay.

At a deeper level: it may be worth trying to discover what's at the root of these various flashes of enthusiasm. There appears to be something out of whack - a call on your life that's not being answered, an element of your personality that's not being fed. One particular analysis is offered in the 'shadow' component of Myers-Briggs: having established what is your dominant approach, it then suggests that as we get more ancient we tend to operate in the opposite way as well more and more. For me that's meant much more openness to emotions, which as an ISTJ are seldom let out to play - but in fact are more visible in recent years.