Break up has broken me

I started dating Nick in february and it as going well for the first few weeks, we waited to sleep together and then i said a couple of things about us being together and he said that he didn't thikn thats what i wanted - he thought i just wanted someone to date and not a relationship, he didn't know if he was ready (he is 27 and has only been on one date before, never had a relationship and only slept with two girls as one night stands) so it really hurt but i could tell we really cared for each other. we kind of broke it off but i said i was happy with just dating but it was kind of on pause and then i went away for a few days to berlin with my friend and whilst i was there a guy was into me and i kissed him but nothing more happened as that isnt really my thing and i was still into nick. when i come home we start dating again and then he agrees to come o my brothers birthday and said something about people thinking he would be my boyfrend and we were drunk and thats when i kind of told him to stop being stupid we clearly really liked each other and wanted to be together so why let it stop us? i told him about berlin and said i didnt want to be with anyone else and he admitted he didnt and then for ages we were in the best most loving relationship once we made it official. then a few weeks ago he asked me about berlin and said he didnt believe nothing more happened and that 'my story changed' when asked about it - it wasn't that it changed i just didnt want to go into full details because i had kissed the guy in the street outside the bar and in the toilet of the hotel and because i mentioned both separately he thought i was lying. i messaged my friend and the guy we met in berlins friend and got them both to confirm that nothing more happened and showed him the messages. we then had a conversation and he told me he had trust issues because of the way friends have been bad to him in the past, by him explaining this it made me realise that it was his silly paranoia getting in the way and i thought we were past it. we had a lovely weekend together last weekend and spent time together on monday and were chatting monday night and then i got a message on tuesday asking what im up to because and he came round he then said he didn't believe me about berlin and couldnt trust me and i was heartbroken he said he had checked on facebook and my friend wasn't friends with the guy from berlin but she had been and had just deleted him he said he thinks ive lied about my past and says hes seen me lie to other people but i honestly don't know what he means other than little white lies like when i tell my friends i'll be ready in 5 but really i'm nowhere near ready. its absoultely tearing me up inside because i truly believe we had something so amazing and if he could just get past his doubt and paranoia then i don't think there would be anything stopping us. I'm not a soppy person and I never believed in 'the one', I've had longer relationships in the past which pale in comparison to my feelings for him and I genuinely believed we were meant to be. I have long since suffered with depression which I've managed well for 5 years but on Thursday I tried to take my own life. I want to be able to move on from this pain but what I want most is to have him back but I don't think that is possible and I feel like I won't be able to move on unless I let him go.

Can anyone please help me?