Amanda isn't in bed the next morning. She left a note, however, which says that she doesn't think Jason will find his home as long as she's here. So she's left, leaving him half of the syringes.
The next few worlds are pretty rough. Although Jason has seven syringes left when Amanda leaves, he's left with only two after being assaulted by a group of teens.
Jason starts living like a homeless man and camping outside his home. While drunk one night, he stands over his parallel self and wife in bed and considers killing Other Jason.
Whoa, bro. You're losing it.
This is the wake-up call Jason needs. The next day, he cleans himself up and heads back to the box. This time, before opening a door, he writes about the first time he ever met Daniela.