I've been dating this guy casually for 2 months & I've recently told him I wanted to take it to the next step.?

He probably does need a lot of time, but I bet he wants to be single for awhile since he's been married. You may be the rebound, so I would try and keep things really light. Otherwise you'll get hurt. He probably does like you, but I really wouldn't put a lot of stock in it now. Have fun with him. Go out on dates, flirt, go dancing, all the stuff he probably didn't do when he was married. but you do need to give him tons of space.