MantaRay has given you some excellent advice (among others).

Bub is also so young, 2 hourly feeding can be quite normal! Bub does that to build up your supply. As MR says, if you're still producing milk, it would be great if you could give bub some feeds (even if it's half/half), because the breastmilk will help with any constipation issues.

All the best. xo