Can’t cum

I’m 18 and I don’t think ive ever came. Fingering myself does nothing and rubbing my clit feels good but I never reach the orgasm. Its like it’s right on the edge of an orgasm and then it just goes away. My ex used to finger me and it felt good but he never made me cum either (he was shit at eating me out and at sex and when I tried to show him what to do and he couldn’t do it) and I’ve tried a shower head and that does nothing so idk what to do. Maybe I just can’t come or maybe ive came before and just haven’t realized it 🤷🏻‍♀️