Just broke up with whom I think was/is a compulsive liar!

Hi All!
I was with my ex for almost a year and I just recently ended things with him. I know and feel i did the right thing but I'm having a difficult time. I unfortunately work with him. I did everything for him and took care of him Better than hes ever been taken care of. !he gad a poor upbringing as well as a tough childhood from wht hes expressed.When He was sick. I nursed him back to health. Got him situated with school,Helped him with his bio course(since i have my BS in bio and hes barley beginning). One thing that was weird was when we went up North for a vacay his family was literally 2minutes away by walking at this football game and left without even seeing him or meeting me. It was a big issue for him but I could never understand why a family would do that especially since thy barely see him.Hes told me his mom had cancer(turned out she supposedly has MS and fibromyalgia), his parent were gonna divorce(never hear about it again) lies about things big and small. At our job I do get hit on a lot but I always decline courtesly but he makes up things that these girls hit on him when they never did. He hid fom me that he went on a date with this chicken head at our work nd the cat came out the bag. I confronted him. He denied it but my good trustworthy friend confirmed and so did the girl. As did this older lady who has no reason to lie. He then tried to turn my friend against by sting he said a multitude of things about me that he never did. Just comparing stories with people over big things and small never, ever added up. I told him I confronted my friend and he never said nothing he claimed and he responded with,"Whatever." I've even helped him at work by training him in things that would make him look good and what does he do? Go and report our boss to HR with lies. He still was able to keep his job. I just am having a hard time completely letting myself accept this. I'm trying to be strong but I can't help but feel played. He took advantage of me and I feel awful. There wasn't anyway I didn't look out for him. He claimed I was his best friend but that wasn't true. I just won't to know how to move forward and how the best way to be at work. I ended things with him a week ago and we won't be on talking terms. He even had the audacity to show up to the church we would go to together but he was never faithful nor religious like me. He looked like a hypocrite when I saw him today. He also seemed like he was always in competition with me. Like if I got attention I was sure he was gonna make up one thing about how this girl wanted him SO badly and yadda yadda yadda. Oh and I was and am not the jealous type. Wish I could have said the sme for him.ugh!