First of all, please do not assume that my FIL's family is not helping- they are, but they all live in different areas and have jobs/ health problems/ finances of their own to deal with. My husband makes the 4-hour drive once a week to stay a couple days then goes back home. We also just began getting visits from hospice, which helps. My main concern is trying to find the balance between mommy and silver-sitter. Not only is my son young and energetic, but he also has a communication delay, which means that sometimes he doesn't understand directions or situations and can as a result get very frustrated with things. My FIL is 78 and does not have the energy to even move from his bed to the couch, much less play with my son or tell him no, etc. Ideally, I would be able to go for walks daily with my son to help with his energy levels, but I am afraid to leave FIL alone, as he has fallen several times in the past, sometimes gets confused, and usually needs help. It's easy to play one-on-one when grandpa's sleeping, but I hate having to tell him no so often when grandpa is awake and my son wants to play. I do not have my son in day care as he and I are not exactly here permanently (as well as his special needs that need to be catered to).
If anyone has any suggestions on how to be effective as both caretaker and mommy, please throw them out for me because I really have no idea what I'm even doing right now (j/k- mostly)!
I noticed you mentioned that FIL is on Hospice Care? If time is short, then continue with staying with Dad-in-law.
If FIL has retirement funds, maybe he [with your help] can hire a part-time caregiver to be with him for a couple of hours per day. That would give you more me time with your son... get him out of the house, maybe find a play date.
You say your husband drives there and stays for 4 hours. Why only 4 hours? Aren't you living there? I'm not sure I understand what arrangement you are describing.