Homosexuality (?), sissy and few more things

Hello ladies and gentlemen!

I won't bore you all with the details regarding my story (you can know more by reading my journal, if you want). In the last couple of months I've changed, but I don't know why.

I always defined myself as "bisexual", since I perfectly knew that I could be in love or be sexually attracted by men as well. It actually never happened (or, when I had some thoughts, they were always of emulation, rather than attraction; it was more like "I wish I'd be like him" rather than "I wish I'd be his boyfriend / had sex with him".), and I always defined myself as "99% straight". The fact is that this summer I started watching sissy/trap/TS vids. I don't really know what changed in me. I started going out with my actual girlfriend almost two months ago. After 2 weeks, when we started going more "intimate", I started having doubts. I become "addicted" to transgendered people, d*ck. I watched a few videos when I was 15-16 and didn't disliked them. Simply I was completely, sexually attracted by girls.

Now, briefly, the questions:
1) According to you: how do you "know" you are gay? I mean: I know that one can't exactely "know" if he's/she's gay/lesbian or not. You are, period. I think that what makes the difference is the acceptance of your inner beeing. Still... then why this attraction? Or, better: why I can't be attracted to girls anymore?
2) [few triggers]: Should I follow my sexual or "emotive" preferences? In my sexual path (beeing pretty lonely I've escalated pretty quickly with P) I've passed through scat, lesbian, feet, puke, piss, and, only recently, transgendered people and "gay". I don't like gay videos actually. I simply feel the necessity to MO to that. It's a strange sensation. Still, when I'm alone with my girlfriend and I O, I don't have as much satisfaction as when I'm alone (keep in mind depression, anxiety, PIED etc.). Sometimes I feel the urge to search for casual meetings with guys, dress up like a girl and be their sissy. When I look my gf in the eyes I see the monster I am... destroyed between sissy, TS, depression...

Sissy and TS are a real trouble today. Modern approach to sexuality is "do what you want". But do I really want this? I mean... is this really ME? I've always been attracted (for example at high school) to girls. I never felt anything for boys. I've been open-minded from this point of view but I've never felt anything. Everything started when I had my first sexual approach with this girl. I simply have lots of troubles beeing "in the mood".

I'm not that happy or friendly guy. I'm pretty lonely and I'm destroyed by the fact that (and I don't even know why) I've been able to screw up everything. When I'm with her everything's fine. The problems come when I'm alone.

Ps. Hope not to be off-topic for the section. If so, I'll move it.