Is your husband articulate/self knowing enough to ask questions about what he wants to know? It doesn't seem that you should have to intuit the right amount of information to convey; he could at least give some clues with questions. Of course you still have to figure out how much answer to provide, but it might be clearer what he ISN'T asking.
Also, maybe keep in mind that sometimes these things come in waves, and maybe you just need to hold on a bit to keep afloat through this one. It helped me a lot, when my husband recently had a lot of trouble with jealousy, to remember how I'd felt when cycling through my own jealousy issues, and to recall that sometimes you're in a trough where everything feels really hard, but the feelings can mellow or fade.
FWIW my husband had similar issues with wanting to know more, with feeling my relationship with my boyfriend was something he just didn't understand. One thing that did seem to help him was hearing about some of the issues I was grappling with there, to realize that other relationships weren't always easy either. (To clarify, these were my issues, not couple issues, so it did not feel inappropriate. It made my husband feel he knew me better and was useful as a support; of course, you might not have equivalent issues to bring up.)