Greeting Ditto, you are not alone. On a side not I'm from the Orlando area, so greetings from ex Orlando folk heh.
I was and am going thru similar experiences with my current ex. My ex wanted space and at first i thought that was the worst thing in the world. I came to realize though that when ppl need space and you don't give it to them, you just drive them farther away. For a while I tried to do everything I could to help show her that I loved her and was there for her, pretty much to the point of smothering her. In the end I ended up driving more of a wedge between us and now we are def taking time apart, maybe forever. At the very least we know have the horriable tag of 'just friends'.
My advice to you is to tell him how you feel and if he still wants the space give it to him. Tell him you will be there for him, you care about him and you respect his need for space. Who knows what could be going on in his head. Trying to force him into feelings or not wanting space won't help. I only wish I had realized this sooner.
You may want to check out the 'Relationship Health' part of these forums. They can help you figure out your feelings as far as your relationship goes.
Just remember to keep yourself healthy. Try and find things to take your mind off of stuff such as gym, reading, etc. Focus on yourself cause there is nothing you can do to change a person's feelings and mind but you can help yourself. You can also be self destructive and bring yourself down, which it seems is the mood you are in now, like myself. It isn't a quick fix, but it is a def something that works and will help improve your entire life. Even if things work out for you and your other, please remember things you learn here and that will help you with any future relationships and help keep your mind healthy.
As for the calling thing, I totally feel you. If my ex called at any time during any day my day would be made and i would be on cloud nine. I used to get depressed everyday she didn't call and esp if i called and got voice mail and never heard back. Even after 5 min i would get stressed and it would ruin my entire day. My suggestion is to stop calling, esp if he is asking for space. It will be hard at first, but it does get easier. Not saying you won't miss his calls and you won't get tempted (and prob break down and actually call) but it will help you a lot. You won't have to worry about him calling you back and stressing. You will know if and when he calls it will be cause he wants to not just to return one of your many calls.
Just get out and do stuff for yourself now. All you can do is tell him how you feel and then the ball is in court. Also, seeing a therapist really helps. I wish i had looked into it sooner but i thought i would just bounce out of it on my own and that seeing a therapist was saying something bad about me and i couldn't cope. I am here to tell you though that they work great. Just do research and find a good one. Also, please see your doc and make sure all is well with you cause stress can cause your body some problems. Again, I waited on that one and will just now be seeing my doc next week, i wish i had made an appt earlier.
---Sorry for the long post but your situation hit a spot for me and I felt like i coudl relate and really want to help