Hard on a marriage

I know they say a lot of marriages break up after having a disabled child. I guess I can see sometimes how that would happen. Last night we had an awful fight. Janey was crying for hours as she hasn't done much lately, but was so happy to see Tony when he got home. He had to go to a drs. appt. at 6 ( he has many, many appts to check on his diabetes and insulin and they are quick appts). He said at first he would take Janey if William would go too, then changed his mind a couple times. I said whatever, leave her if he wanted to, but William wanted to go and they were about to when something annoyed him and he started to leave (at 5:30, the appt. is 2 minutes away). I called him back and asked him to take William and Janey, and he was FURIOUS over it and was yelling in the driveway as he took them, things I am sure he wishes he hadn't said about me. I was quite hurt and when he got home we were fighting a lot. I get so burned out by Janey sometimes and it seems like he doesn't get that I have to deal with her NO MATTER WHAT if he's at work, but when I am trying to work or make dinner or anything, he deals with her IF there is nothing else he feels comes first. I know taking her to a drs. appt. is not the best situation, but William is 14 and easily capable of watching her in the waiting room, and Tony did offer. Oh, well, of course the silly details are the tip of the iceburg, we are both just in over our heads lately and overwhelmed with financial problems and not really knowing how to help Janey best and our falling apart house and all. I shouldn't complain but sometimes I do anyway.