I really admire how in tune you are with how your brain works and your moods, you have a lot of insight!

It sounds like you're on a rollercoaster ride of being affected by (or quite sensitive to?) what's going on around you, in your environment, and this sounds confusing and very difficult, as it would be for anyone

The only other thing I'd say is that precisely since your moods seem to be dictated by your interactions and environment, perhaps you're on less of a mood rollercoaster, than an emotional roller coaster? BP moods tend not to be terribly affected by interactions with others, though it's true that everyone has their triggers (commonly, lack of sleep and lots of stress, but as I say, everyone's different).

Maybe therapy might help to maintain a more stable sense of self and to not be as affected by your environment to the point of being on this roller coaster ride. You could also consult a pdoc, if you don't already have one, regarding diagnosis. Best of luck to you, I hope the professionals can help you clarify some things and help make you feel much better!