If you notice the signs of mood swings comig back, I'd def recommend you at least start on meds. Maybe start by speaking to your medical doctor about it first, and if he cannot help, he can refer you to a pdoc.
At 18 you are still irresponsible and it's hard to convince oneself that the meds are necessary.
I'm glad you're considering help, as BP really cannot be left untreated.

With regards to T, is it possible for you to just go back to the one that you liked?
Hang in there - we're here for you. It may seem lonely at times, but the PC family really does care
((HUGS))