Is this relationship working?

This is going to be extremely long winded. But anyone who reads this and offers a little advice, it will be much appreciated.

It started back in July, when I met a guy (as a friend), who then had to go out and work abroad for a few months. We both were in relationships- but broken ones. He was abroad for months, and I was home, studying, but during that time we talked every single day. We both ended our relationships, after falling completely in love with each other, and a few months after, decided to date properly.

Ever since then has been a whirlwind of love. We known each other exactly 10 months now, and have been together properly for 4 and a bit. But I would say, emotionally involved for 10 months. We have both said we have never felt this way with anyone before.

He met my parents and I told him, my father won’t necessarily be as talkative, as with previous boyfriends, he hadn’t. It went the oppisit way, my dad adored him, the first out of anyone I’ve brought home, it was amazing. It brought me alot closer to my father too. Then a few weeks ago, my father died. It was a sudden heart attack, and me and my mother were both there. My boyfriend was abroad at the time, working, I was due to fly out and meet him for the last two weeks, of course, I didn’t go.

My boyfriend was devastated. He was there for me day and night and phoned me and was there for me the whole time we were apart, he couldn’t come home because of work, but he came as soon as he could. During the weeks apart, we felt so strong. But the last week he was due to fly back home- things changed. He started replying less, getting angry at me.
I completely understand why, I am acting irrational because I am a mess and it is natural for me to crave someones attention. But I asked somthing- have you been talking to your ex recently? He said yes. But only because she is away travelling. She admitted she still had feelings for him so he didnt talk to her for a while, but when she went away travelling, she seemed to be starting to act normal again so he said it felt like they could be friends. I was upset, but I accepted it.

I came and met him at the airport, but things didnt feel right, I dont know wether this is in my head, but it just didn’t. He didnt act as lovey dovey, he was jet lagged and completely exhausted from work and all of what had went on. So the few days I spent with him were an emotional roller coaster, one minute we were telling each other we loved each other the next we were arguing and I was upset.

I clicked onto his emails accidently, as it was signed in automatically, and the amount of emails in that past week were the sum of every-day emailing. I confronted him, really upset and asked why he was talking to her more now, than he has ever before. The emails wernt at all love related they were merely jokey and friendly, light hearted. How you would email a friend. He showed them to me. But they were every day emails. Of her travelling experiences and his work life and all. He was sending pictures to her, the same ones he was sending to me. But he says it is all innocent and he loves me so much, but he can’t stop being friends with her.

Somehow, in my mind, this does not feel right at all, and we have been rocky ever since. Is this because I am fragile anyway and I am over reacting? Or should I really be worried. Because I truly feel he does love me, but I am maybe caught in a love triangle. Please help.