Not sure where else to turn and could do with some much needed advice...
My partner and I have been together for 9 years (not married, no children, currently renting an apartment). His passion is running. I can't run for toffee, but he loves it. In November/December he met someone at a running event he volunteered at. She is married and had children, he soon became friends with the family but I noticed a big change in his behaviour - he started running more often in the week (3/4 days) and I felt like something wasn't right.
In February he was doing some work on our shared laptop and when he was finished he gave it to me, he left his Facebook open and I did have a look because I was intrigued. There were hundreds of messages from this women - they weren't sexual or romantic, however she would always send a 'Hi' at 5:50am which is when we both set our alarms for work. I confronted him about the amount of messages and the fact they were booking on to a lot of races together. I asked him to show me his phone and there were a large number of calls from her in his call log, they had snap chatted, she sent him messages on his personal and work email, I could go on. Naturally I was devastated - why did they need so much contact?
Anyway, I'll try to cut a long story short - I told her I knew about the messages and told her to leave my partner alone, she agreed but completely ignored me by sending emails instead because she thought I wouldn't be able to see them. I told him he couldn't see her. They are still carrying on - they are even doing the VLM together today! He tells me white lies, is as though he tries to defend her. In a recent argument I asked about sex/sexting/holding hands/kissing, etc and he said no. He did say that he was unhappy because I wasn't spending time with him and I wasn't supporting him and his running, and he said she was always there and put more effort in to him than I did.
I've had so many arguments with my partner that I'm now sleeping in the spare room. I can't sleep or eat anymore. My family live 3 hours away so it's not like I can see them. I feel depressed because I felt like 9 years is a long time to throw away. One minute he's telling me he's unhappy and he's enjoying a friendship with another woman, the next minute he tells me he loves me and never wants to split up.
Any advice would be great.