Thank you all for your replies!

We've been doing alot better... I think part of the culprit was that we were talking on the phone
at least once a day, for 30 minutes+, and him not being a phone person... [he's in the Uk now, forgot if I mentioned this or not].
Anyway, I told him my needs, and backed off of calling him all of the time, and he responded by sounding happy to hear from me, and making the effort to call me himself. I think our daily conversations get kind of dull, because not talking to him for a couple of days made us both more excited to hear from eachother.
I've also been giving him (and myself) a break from questioning his devotion, trust, etc... I get insecure about these things, but the reality is that we can only do so much with him across the ocean.
My only fear now is that he's becoming depressed again -- he sounds worried and downhearted on the phone sometimes. He won't talk about it on the phone(although he will in person) but even if he does he's always refused to get treatment... the one time he finally went (for me) he didn't tell the doc any of his problems, saying it was just me that thought there was something wrong with him... I don't understand the logic, he admits he needs help, just can't follow through. Why is this??!
Thank you all!
Jessie