After 2years together..our first year was a joke?

Hi, I'll try to make it quick.

we been together for 2years, planning engagement soon:)

however after a perfect relationship i recently found out about few things..

1. in first 8months of our relationship he stayed over at many girls houses. just on sofa after party but i was never told.

2. spoke to his ex a lot about meeting up (as friends)

3. had pictures of picking up and hugging girls.

4. went on a 7day holiday with just girls without really telling me it's just girls.

5. and few other things.

he's not a player, but a cute guy who has many friends no matter about their gender. he never would cheat etc etc, so i know he didn't.

also after going away for work 7months ago (for 5months) he was very friendly with a girl..she kissed him. and he kept being friends with her. let her stay at his house there etc. hanged out. and went on a round the country in a van for 3weeks trip with just girls....

i love him and he changed so much. he loves me loads. he done nothing since and always keeps apologizing about it.

but i can't stop thinking about what happend last year :( :(