Hello people, soon i will be 25 and yet i have not had sex or a girlfriend for over a month. The problem i see is that although i made a good impresion on women i am afraid to escalate. For example the last years i have met some girls and that's what happened

1) When i was 21 i met my 1st girl, she was older than me, more experienced, we kissed, we were in a "relationship" for about 2 weeks but she had a lot of issues so we broke up.
2) After 1-2 years i met a girl online but she was living away, we talked a lot via phone etc and sometime it happened to be at her town so we kissed, she told me she had her period (idk if it was true back then) we continue with dates kisses the next 2 days until i left again and after some phones 1-2 weeks later we stoped talking.
3) At the end of 2012 i was talking to 2 girls that lived out of my town, the same month both of them visited me. The one i liked better came but i could go for a kiss and generally was a bit cold around me (although she drove for 3 hours just to see me). The other one also came at my town we went out, we kissed and after she left she invited me at her town where she was in college. When i went there for the weekend i stayed at her place i tried to have sex with her 2 times but i could not get my dick hard so we just do the other things.
4) Before 4-5 months i met a girl through a friend, there was some flirting between us that i started it first but since there were always friends around when i was meeting her i did not make a move. The last 2 months i asked her out, we went out like 3-4 times alone and i was afraid to go for a kiss, 3 weeks ago i was seeing her again and she was leaving my town for a summer job. She iniciated the kiss, we made out some times and after a week i went to her town with my friends to meet her. She had a break of 2 hours before work, our friends were at a club there and we went alone to her place so she can change clothes from work so we can meet them. When we got home we started made out, she went to take a quick shower and then we went to the club. Since she did not want to show that she is with someone we were both discreet around our friends and after we left i saw her a bit "cold" at our communications and yesterday she told me that we were a bit late and maybe it would be better to slow things with us down to see how it will go or postpone them.

As you realise all the above cases have in common that i am a bit anxious (maybe since i am a virgin) to take things further. I really like the last girl but i do not think that it will continue but i do not want the same thing to happen with the next girl i will meet. I am tired of being 25 and not having a single relationship and i want to change. I really need to hear an advice guys because i am starting to getting worried about my self (of course i do not show it when i am with friends or girls).