I think one of Fr. Thomas Hopko's maxims for Christian living is probably a solid piece of advice both for sane living and also, as a consequent, not burning out (it is also the one that I personally found most memorable if not most personally disconcerting). "Be a normal person," he says. Normal people do not concern themselves over whether going to grandma's Episcopalian Christmas concert breaks the canons, whether they should call the religious of other Christian denominations or even other religions by their proper titles (the sane answer is that common decency says that we do), whether the Holy Spirit turns Catholic hosts into the flesh of Christ, etc. (none of these examples, by the way, are supposed to be specific examples, just general examples of questions that get asked a lot, so I'm not singling anybody out here). Oh, and also, normal people do not calumniate members of the clergy they have never even met.
Now, I am not saying that one should have no zeal for Christ our God (God forbid), only that there are abnormal and normal ways of using it. Whatever zeal you have for God, turn it towards prayer, fasting (to your ability), almsgiving (this one may not be too feasible for a teenager), reading the Gospels, living according to the Gospels, serving your parish and community, and repentance. Speculative theology, canons, theological debates (this goes beyond the exhortation that we should know our faith well enough to defend it; once a defense has been presented, if it becomes clear that the other person is interested only in being disputatious, then refusing to participate any further is not a bad idea), or the plight (or the just and deserved forced resignation, if one is so inclined to think this way) of Metropolitan Jonah, on the other hand, are probably all unhealthy things for us to direct our zeal for God into (and they likely do not please God very much, if at all). Live a life in Christ (rather than a life directed towards only thinking about Him in an academic fashion), and the rest should fall into place.