Ok sorry I am having a hard time I have to use phone and it's hard to do for me. So sorry for disjointed replies.
Ok here are a few more suggestions. 1-the pump has 2 issues. One, it is not the right kind for what you are doing. It is meant for working mom with well-established production to use a couple times a day. 2, it is old. These kind of pumps are designed to be used by one mom for one kid. After that they often start to not work properly.
If you cannot rent a hospital rental grade pump, at least troubleshoot the one you have.
I also strongly suggest the excellent book making more milk.
I also think using the Sns again for at least some supplement is a good idea
And/or give baby small amount in bottle before and/ or after nursing instead of totally replacing nursing session with bottle. Again the idea is to encourage lots of nursing. If baby is full from bottle baby less likely to want to nurse with normal frequency.