I may be a little lost here. Your bio and post says you're bisexual, you got a crush on someone, watched some girl on girl porn cause this person was on your mind and now you're feeling down. I think your issue with this is less about being gay or any other sexuality and more about your affection to anyone that likes you. If you like someone and you get aroused by them thats totally fine. Theres nothing to be ashamed of there. You can still question why you like them and whether or not it's a fit for your life. Rubbing one out is a common tactic people use to determine if they want to pursue someone romantically/sexually. *
In my opinion, if this frustrated you enough to watch some lesbian porn, you probably like girls at least a little bit. What it means to you only you can discover.