@Ru**
you shouldn't have a problem getting a 90 day Non-O visa from the immigration office out at Chaengwattana as long as you have at least 15 days left on your current stamp AND as long as you meet the requirements paperwork wise.
That's why I said go out there WITH your thai husband and get the hand out from Section C-1 (the section that issues VISAS inside the country).
The reason you need 15 days or more on your current stamp is that your application will go under consideration for 14 days before you go back and get the Non-O visa and a new 90 day stamped inked into your passport.
Then after that 90 day stamp runs down you can apply for the yearly extension in Section L out there..
Good Luck, I think you have most all the information you need.