Quite simply you have to convince yourself you don't care. Before University I had a two-year 'drought', you might say. I'm pretty sure women can smell the desperation on you because I just had no luck with women. Now, call it coincidence or whatever, but I decided during my summer holidays that I just didn't care anymore - sex, relationships, it was all too much effort. I just decided I was going to forget about sex and just enjoy my time with friends and so on.
And whaddya know? Three weeks into my second year I get into an easy-going relationship, with regular 'good times'.
Long story short, just forget about being pressured. Just enjoy yourself and talk to women as though they were your mates, rather than 'potentials'. They will feel comfortable because you are and you'll be able to impress people with effortless cool, charm and yada yada yah.
And as far as the prostitute goes? Definite no-no. Losing your virginity by a certain date is not at all important. Who you lose it to, however, is. Doesn't matter if it's their first time or not, but don't do it with someone you've drugged, blackmailed or purchased - none of these are something to be proud of!