Difficulty Getting Hard and Staying Hard and Orgasm During Sex

Hi, I'm gonna be totally honest here even though some of the stuff is pretty embarrassing... so please don't judge! ;)

I'm 28 and haven't had a lot of sexual experience before. I've had sex about 20 times overall, and have orgasmed during sex about 50% of the time (but unsuccessful during the past 3-4 times and have had to either give up or finish off with a blow job/hand job.)

Having read some of the forums and suggestions here (and kinda realizing it myself too), I think my main problem comes from watching too much porn and masturbating to it too often. I masturbate on average once a day (so some days I don't, but some days I do 2-3 times... sometimes I don't even get hard and orgasm if it's the 2nd/3rd+ time for the day). I'm planning on not masturbating and watching porn for a little while and see if that affects my performance. Unfortunately, I don't get regular opportunities to have sex (have never been in a relationship with sexual intercourse involved... all experiences have been one nighters or with pros).

Most recently I tried a pro to avoid the usual anxiety/embarrassment that comes from not performing properly with a normal girl. Even though she was hot and I hadn't masturbated for 1.5 days, I still couldn't keep full hardness throughout the sex (we tried different positions and I was half-hard most of the time). We had to finish off with a hand job while I was thinking about some of my fantasies (thinking about particular people and situations I sometimes masturbate with).

I'm wondering if anyone out there with experience and knowledge thinks this issue comes from anything other than me masturbating frequently to porn (or maybe the way I masturbate?). I will update in a few weeks after trying to keep my masturbation down to once a week or something, with little porn involved. I may try a pro again to see if this has worked if I'm not able to find anyone during the time (which is not an unlikely outcome), of course money-wise I'd like to avoid using a pro if I can. I'm very concerned about embarrassing myself with a girl that I actually like and want to make sure I have solved this issue before that situation comes along.

Thanks for the help!