AITA for being mad at my dad demanding I help my mother?

A bit of context: my mother was just diagnosed with osteoporosis. I’m from Mexico so non-private Healthcare is very hit or miss. Thus, she’s gonna need to take an expensive medication every few months and she can’t miss it, so if public Healthcare can’t provide, it’ll be out of their pocket.
Now my parent’s financial situation isn’t the best, but they manage. I’ve been helping my mother with expenses here and there in the last few months, since I got a stable, decent-paying job.

Just a few hours ago, my dad called me out of the blue, reminding me to pay for my car’s insurance, and he adds out of the blue "Oh, and also pay for your mother’s this year, and also she says you haven’t been giving her any money (as in, periodically), so you’ll be giving her X amount a month from now on".
Like I said, I’ve been helping out my mom, and after she told me her diagnosis earlier today (before talking w/my dad), I was thinking to help out more. What bothers me the most is the audacity of my dad to demand money from me to "return what I owe them" after I went to community College and paid for my expenses since 2nd semester when I got a half-time job. I told him plain and simple "I do this bc I love her, so don’t you go demanding it, because if it was any other person, they’d tell you to go f yourself and now they won’t help".

Now, AITA for being mad at him? He thinks he’s so smart by just saying "I won’t discuss this any further, pay the cars insurances and give your mom $X a month" so I’ll look bad saying anything else than "OK". Also, when I talked with my mom earlier, she didn’t ask anything of me, she never does. It’s me that insists on her accepting the money I give her for expenses when she’s in a rough spot or needs to pay my doggos vet bills. My problem isn’t with her, it’s with my dad.