I recently ended a 3 year relationship. He cheated on me about 2 months ago. He'd been emotionally abusive and manipulative throughout, so once all the dust had settled and initial devastation wore off, I felt amazing.
Anyway, I have made a very bad choice :( I started a new job recently and went out with them, ended up sleeping with one of the guys I work with... I feel like such an idiot. I worked with my ex for ages so swore I wouldn't get involved with anyone from work in any capacity because of how awkward it becomes and I managed to go against that in a matter of weeks.
And my idiocy aside, I also found out this new guy is friends with my ex's best friend. So a part of me is really sad and upset that he'll probably find out I have 'moved on'.
I don't know what I'm asking really, I've just spent the whole day feeling guilty and sad and confused. I used to have ONS fairly frequently when I was younger and at uni and didn't really feel bad then I don't think but I just feel awful about it now for some reason. And I really miss my ex, obviously for a multitude of reasons I can't go back there, but I feel so sad and alone. I hate starting new jobs anyway, makes me anxious not knowing people very well and now I'm sure they have a great impression of me 
also I was loving being single and having all my time for 'me' and being able to unapologetically do exactly as I please, and not have to worry/stress about my ex as I often did, but for some weird reason I feel like this happening has erased all my progress and I'm just back down to square one again :( I really miss him and our relationship and I miss the security of someone being there. Right now I just feel alone and like everyone is going to judge me to high heavens.
Please tell me it gets better and it isn't as bad as I'm thinking?