HELP!! Need second opinion.

Ok so I recently met this guy and I do like him. We get along well and it's like we compliment each other but we haven't known each other long. But he reminds me a lot of my ex in both negative and positive ways. I'm really interested and I'm trying really hard not to go off the deep end over him. I'm not sure if I'm over thinking or maybe I should just walk away. Like I find myself getting mad when we doesn't reply right away or automatically assuming he's with another woman. I don't really have a right to feel these things do I? We did just start getting to know one another. Ugh I'm not sure what to think.