trip tires and stress

So yesterday we headed from Ohio well we had to fill up our back tires the  day before cuz they were low well we figured well its cold here so thats normal. WE were WRONG! the next morning we had to get air AGAIN..  this should not of happened in under 10 hrs from 11pm-7am we long a lot of air. to the point our PSI warning came on. so we filled up got about an hr away and the warning came on again.. so we filled up by this time I was stressing cuz we were traveling to MD and filling up every hr was not possible when driving through mountains. so we drove about 2 hrs with the warning on. I texted my mom and asked her what we could do she mentioned fix a flat..  so the first gas station that we came to we stoped hubs went in and found something like it that also puts air in your tires. after that it held for the trip. We were both very concerned our steering wheel was shaking horribly, and we just didnt know why. So we Got to my Step-dads house stayed there for 2-3 hrs went  out to the car and the PSI was from 38 to 20! just from sitting there so we used his air compressor and filled up and went to my moms house. We got there okay and tire pressure held but after we parked and the car sat for a hr the hubs went out to get something and checked it by that time it was okay it went from 38-30. then he checked it before we went to bed and it was 28 we figured it should hold till morning to where we can get new tires. Well we got up this morning around 8 he went out to the car and said babe call Rex we cant go anywhere PSI is at 3!!!  so my mom and Rex came to the resuce again!  brought the air compressor and put air in well we drove it to rexs then Rob and Rex went and took the van to honda around noon. to get new tires we knew we needed them but we didnt have the money we have "run-flats" on the van (not by choice just the model n yr of van). So thats about 250 a tire and 109 an hr for labor ! so all together 730-740 bucks for 2 new tires! stressed over money as it is living on a military budget paying for our sons headstone child support and having 2 young kids. we need new tires! they were so bad the gel that makes them run-flats was seeping through the tires. that has been our trip for the past 2 days so stressful and monday we drive an hr away for hubbys surgery consult

thanks for reading
<3 always