I think there is something developmental going on, in addition to teething and you DH going away. My DS is very similar in behaviour, we have thought maybe scared of the dark, so have left a light on, too hot/cold. We have often resorted to staying in his room untill he has fallen asleep, there is a matress on the floor at the monent, due to increaing cold and for my comfort at 35 wks PG. Also, I or DH can doze or fall asleep if able, DS can be chatty. We have on occasions left him to have a cry, we had 5 mins or whinning this morning before he resettled.
I hope things settle down for you, I know DS will settle for DH quicker sometimes becasue he has missed him all day and likes his dad, I suspect the troubles you are having is more becasue your DH has gone away. Good luck, I hope your DS improves soon.