If the burden is so great on Jeff why does he spend so much time working to screw it up? He's deliberately horrid to people and shocked when they leave? If Monroe is so much of a distraction why not move Gage and the baby into a small apartment until they can solve her medical issues? Why try to force Gage to ignore their child?
It's obvious it never occurred to Jeff that Monroe would be the center of Gage's universe (as she should be the center of his). He's too selfish, too petty and too sick to understand.