Mist,
Does your hb travel often?
My hb used to travel often, left me with 2 kids. Most of the time i also fetch my kids back myself as he reach home 8pm or later. It's not easy to handle 2 kids alone. Mmm, slowly Xavier health will be better as he gets older. By 3 years old, his health should be better. Of cos there will be time when kids sick, hb not around. Still can handle, if tired take mc or leave to rest. I feel that after become a mum, I'm tougher and stronger. Don't worry, we learn and can overcome one. Stress make us stronger.
If I were you, I will get a maid and get mil to be there for a few months. If the maid is ok, mil can go out sometimes if she wants. But must come to help out a few days in a week. For the allowance, get hb to explain where can't give as much as neighbour.
When number 2 comes, then see whether mil handle baby or maid handle.
Depends on luck, some people get good trustworthy maid. Some get blur, cannot trust maid.