So, do you just want 'sex' or do you want a 'life partner'? Good for you if you're looking for a serious relationship, but you can 'over think' these things. Usually most people have to go out with at least a handful of people until they find someone who's right for them. Hardly anyone gets it right first time (or second, third, fourth or fifth for that matter). Perhaps, rather than putting too much weight on the whole 'life partner' thing, try to lighten up a little and try to find someone first who you find attractive and get along with? That's a step in the right direction?
"i am always worried about what girls think of men like me"
What do you mean by this? Do you have some kind of disability or are you overweight? Or do you mean the fact that you haven't had sex yet? I think if you met a nice woman and you got along well and you went out on a few dates, liked each other, enjoyed each other's company and wanted to see more of each other etc. etc then when you were starting to get a bit more 'serious', you told her you had never been with a woman she would be most intrigued and probably happy to help you out! I know I certainly would!
If you're getting addicted to porn, this is not good at all. Also watching too much porn will give you a completely distorted idea of what real sex with a real person is all about. It might be a good idea to use the services of a professional? Maybe that sounds a bit extreme, but perhaps extreme measures are called for here if things are becoming unmanagable? You will find prostitutes can be pretty sympathetic about this kind of stuff and may be able to give you all kinds of good advice about the simple mechanics of love making too. It might sound shocking, but it might be worth considering?
"The only thing to do with good advice is to pass it on. It is never any use to oneself." - Oscar Wilde