Sorry you are here, but there are a lot of good people here that you can lean on.
Knowing a little more about what got you in your sitch might help a little bit. You have some positive signs, he could have had the D but put it on hold. He is wanting to know if you are going to see each other. I would read this that he wants to see you.
Not pursuiting and calling frequently is a good thing but if you want your M to work at some point you are going to have to start talking to one another. I would start with small talk and if he brings up the R then let him talk about it. Responding to his initiated text about your birthday would have been a good place to start. If you want to be a little "mysterious" then wait a little bit before replying. While I have been separated, the rule of thumb I am using is if my W initiates a dialog (text, e-mail, phone con) then I will reciprocate else I for the mostr part give her her space. When we do talk I never bring up the R or things related to the R. If she does then I for the most part listen and try to understand her POV. Don't know if this helps any.
Best wishes!
TwinDad Me 39, W 36, M 11 W - MLC, WAW???? 2 Kids B/G 3 YRS Old Start of the Long and Bumpy Road..... On the verge of piecing.....a new beginning