I meet a guy at work and we worked together for about 8 months then he left but since then we kept in touch and we got on well and have been friends since then... I have now known him for nearly 3 years.

Anyway we got on really well in work and I always enjoyed his company and I think he enjoyed my company also. We would chat online/text quite a bit. We always got on well and had a laugh together but I never thought anything of it I just thought we were friends then someone mentioned that we were quite 'close' it got me thinking.. and I gradually began to think I liked him. Now I have liked him for 2 years.

I have never liked anyone as much or in the same way I have liked him which is what is confusing me. I just liked his company and I love chatting to him. I always want to be with him and I think about him EVERYDAY no matter what I do I can't get him out of my head! I feel so down about it all because I have no idea if he feels the same.. we lost contact for a bit but now we are back in touch but he doesn't chat to me quite as much as he used to. I would be devastated if he didn't feel the same about me.

I had been feeling down on and off cause I thought I was never going to meet a man... maybe that's why I am obsessing over this guy. But I feel like it happened randomly that we meet and I just began to like him. Hes not the usual type of guy that I would go for, but still I like him a lot.
Perhaps I even LOVE him... I haven't fallen in Love before.. but I also have never felt this way about a guy before.

DO I LOVE HIM! What does it meant to love someone?

The only way to find out how to define what you feel is to take a risk at talk about it with the one you have feelings for, or its only a label. Means nothing.

Well, your choices are quite clear, you can either -
Risk friendship and ask him out to see what his true colors are.
Or you can get back to talking to him a lot since you enjoy his company.
My question is that if you've never loved before, your first love usually is hard to get over. Usually ending up with knocking off all contact with them. Being the only way to get them out of your head.
I suggest trying to get the conversation kicking up like it was before, if it can't, and you don't feel anything, it may of just been you. If your attracted to him for the comfort you feel talking to him, hey, I say go for it, ask him out. If you don't feel anything anymore, it may of just been your mind thinking its love for the first time, just because you've never had someone like that to talk to.

If this way helpful , I wish you luck in your friendship or relationship.

If you love someone, you don't have to question it, you just know. In your case I think you like him a lot and it is something that could blossom into love the more you get to know each other.