Family drama (need suggestions) kinda long

vspek

I am a lurker here, but would really like some advice. 

Long story short, my mom does not work and when I was pg with DD over 2 years ago she said that if we'll buy a house close to them, then my mom will be able to babysit DD at least 2 days a week. We bought a house 18 miles away from them in the hopes that she'll keep her promise. After DD was born and we moved she said that she will not be able to help because she is sick. (She's been using the same excuse for a long time). She just has diabetes and keeps on inventing other sicknesses in order to not help. For her to stay with DD she would need to be at our house by 7 am and leave around 6 pm. 

When she refused to help with DD, we had a really big fight and DH said that my parents will not be allowed at our house. Then 6 months later DD got sick in day care again and neither one of us could take any more days off work, so I told him that whether he wants to or not I'll be asking my mom for help. She stayed with DD for those couple of days when she was really sick. From there on she started coming only when we had no other options and it was either one of us was to quit or she would come in and help.

When I told her that I was pg with DS, she was really surprised that I was not going to have an abortion and kept on telling me that I am crazy to have two kids 2 years apart. None the less she said that she'll help when I'll be at home with them. She did help for a week and a half. After that she said that she is really tired and will be coming every other day. When I called her and asked when she'll be coming next she said that she was tired after their vacation and will come either on Wed or on Sat (DH is at home on a Sat). She did not come in on Wed even for a couple of hours, but came in on Thursday (said she'll be here all day, but was here for only couple of hours and most of that time she was showing DD cartoons), while I went to the store to get some food.

When I came back she said that she had to go home in order to not hit traffic and left.

Essentially the issue is that she is not dependable and DH is very much pissed at her for promising something and not keeping it. He told me that we'll need to move when we are able to sell our house, so we can afford a nanny and not have such a horrible commute to work. First I was a bit against it, but now I am sort of agreeing with him. My parents think that we are loaded and don't see our expenses (most are either for the house or the kids). At the same time they are complaining that they have no money to even give gifts to their grand kids.  

 DH does not want to go to their house for a visit, but they keep on being upset that we don't want to visit them. Explaining that it's hard is not working. 

What would you do?

When I asked my mom for help, she said that it's better for us to hire an au pair for the kids, because she is too tired for help. (My mom is only 48 years old). She also keeps on telling me that I am crazy for having another baby, but at the same time she says that she loves them like crazy, but won't move a muscle to help.  

TIA!