Oh turtle (((HUGE hugs)))
Is there anything we can do?
I have a few points on the whole thread -
Firstly, have you tried Orajel yet? It is amazing (I tried it myself last night as I have a wisdom tooth coming through with an ear infection on top) - totally numbs the gums, really helps DD when she is teething and I have a spare tube if you want it.
Secondly, you are an awesome Mother and you really need to start believing that (truth be told, I have always seen you as a bit of an uberMummy!).
As you know, my DD and your DS have had similar issues at similar times and seem to be again with regard to sleep (maybe they send eachother secret messages?). She is up 8-10 times in the night, sometimes she is screaming with frustration and other times she is giggling and almost singing us songs. I also cosleep - not that it helps. I just repeat to myself the mantra that this WILL pass, it won't go on forever and it does help me to try and have a bit of perspective.
I also think that like other have said you are comparing your experience now with your experience before with other peoples children - DD sleeps like a dream at nursery, 3 naps a day, same time roughly most days. No chance of that at home!
Thirdly, your husband is being a total utter shitbag, why does he think he doesn't have to put in 50% of the work now when he put in 50% of his genes 18months ago?
If you need ANYTHING, please get in touch, I have been through very similar as you know and it is possible to work through it (relationship wise, shan't profess to knowing jack all about making babies sleep).
Maybe we could swap babies and see if that helps!?!