I do feel for you, OP, it is incredibly hard when your sex lives are mismatched. I'm surprised, however, that I can't see any mention in the thread of one question - What contraception are you using?
I was so scared of getting pregnant after having ds (no trauma, just the usual total overwhelming lifechange and exhaustion of having a child) that penetrative sex dwindled to almost nothing despite me being on the pill, and in fact after a while nonpenetrative sex went the same way. I changed to the minipill and that killed my libido absolutely stone dead. Sadly, I barely noticed the difference, I was so knackered.
I'm not going to give you a recipe for things that have helped us, for two reasons - 1. I'm afraid you might go to your wife with a list in your hand saying 'these guys fixed their problem this way' which is absolutely the opposite of how I think you should work, and 2. we have sex about once a month, which is a lot better than it was, but clearly not enough for you.
The only thing I am going to say that really did help was patience, on dh's part (ds is 9 now) and feeling beloved and wanted by my husband. Only you know how to make her feel that way. And not in a 'I love you, can we do it now?' way. That's a problem, though - if she is not giving you love back, it's so difficult to generate that from nothing - that's why they call it making love. I can only recommend that you try, though.