I guess he is asking me about my well being.
In fact, I don't think so. 幸せ usually doesn't mean normal well-being but only the full-of-joy state, that like whoever has their child. It's not a word you use to ask if somebody is fine.
In this case, unless it's typo or mojibake, the final ？ represents some degree of unsureness or hesitation towards previous words (or, choice of words). It's bit slangy, orthographical (non-verbal) usage of the sign, but quite widespread at least on the internet. They as often as not enclose the question mark with parentheses （？）, in that case, more unambiguous to readers. With all of these it's still open to wide interpretation, but I guess he want to tell something like:
It hasn't hit me yet, but I suppose I'm really happy.
Is that so-called, I couldn't be happier?