I can see where you coming from. If you are uneassy around people then you should juat nit use tgat as an excuse but push yourself into social situations. Comfort and confidence will come from experience. Its like training and warming up.
Dating sites are good to find dates, especially for girls theres a lot of choice. So find someone with who you can chat well and tgen after week or two jump into a date. Really it takes jump to meet someone from internet, but its worth it. As for the sex, decide if you want to just get over it or make it special.
Doubt kills more dreams than failure ever will