Girlfriend Unhappiness

Hi and Merry Christmas.

I am 21 and have been with my girlfriend now for 7 months. I am so happy and have never felt more comfortable with anybody else throughout my life. I've been ill with tonsillitis and she has been great, I have been stressed with work and she has helped me out immensely. She has been fantastic.

I have known her now for 3 years and a bit. When I first lived with her in shared accommodation in the 1st year of university, I unfortunately did kiss her a few times and on occasion, went a bit further. However, whilst we were all very tight as a flat, I was really upset to learn that when she would go out, she would get with/intend to get with 1-2 guys, get ridiculously drunk and then message people, find out whether they got with anybody, etc. etc.

In the 2nd year, we never saw each other despite living two roads away. Perhaps due to the awkwardness of the first year. Though I was upset to see pictures on a social networking site of her kissing other guys when she had no time for me. I felt used.

In the 3rd year, I took a year out but then towards the end of that year, we started talking again. We even went on a few dates to places like the Lake District and to pubs and to the cinema etc. I felt so happy again - I thought I met a new person all over again, it was so easy and comfortable, she looked gorgeous and we both seemingly loved each other so I asked her out.

Since, (in my 4th year), I am the 'love of her life' and she is so sorry for the way I was treated in the first and second year. She loves me so much as does her family and her personality is amazing. However, recently, I found out she had sex more than me and in more 'unjustified' circumstances e.g. on a cruise ship for 2 weeks with a guy, on a beach on holiday with a randomer, with a guy 1 year younger on holiday, with a guy from a club night out (i.e. one night stand).

Whilst I appreciate that people have past histories, I felt really sad once again - is this normal? I spoke to her about it and she wished it never happened and that i was the 'only one' but I can't help but think that sex with people with randomers is really bizarre, for something that is so personal with someone you should love.

I love her but I can't stop thinking about it and the amount of times she got off with others. Am I being paranoid? What should I do about it? Even when I have sex with her, I sometimes don't feel 100% 'with' her as she might think of others at the same time.

Please advise, thank you in advance :-( xx