Am I gay if I cant have an erection?

Well that's a stupid question, I don't think i am but I only had 2 girlfriend's when i was 15 and those where the only girlfriends i ever had and i felt very different down there when i was dating them but it's like my thing was thinking for me and wanted something very bad.. but now that i've been single for a year i haven't gotten anything since i dated them,I tried looking at a few pictures on the internet (if you know what i mean) but i cant really get anything i'll get a little pump for like 5 seconds and then it goes down. but that's it.. I just want it to stay longer maybe im just so paranoid, i have no attraction to males so nothing to worry there maybe im just turning into an asexual... by the way i try to fantasize about women..