Sounds like swollen glands. Probably from Herbicide exposures, could be from the paint fumes also. Even though the paint is low-fume it still has some VOC's in it (volatile organic compounds) and if you are sleeping in your room after newly painted, you are breathing it in all night.

your system may be overloaded from both herbicide and paint fume exposure at the same time. recommend sleeping elsewhere until paint fumes outgas, and not being in the room while it is painted. do NOT expose self further to round-up.