Houston transplant from PA and I need help using my HVAC system

I’ve been in Texas for about 7 years and I thought I would get used to the heat, but I haven’t really. I find in the winter I am constantly switching between heat and A/C as the 80 degrees afternoons are so hot but Texas mornings are so cold! I have a baby in the house so I like to keep him comfortable and will switch between A/C and heat often.

In PA, you have your a/c on in the summer and heat in the winter. I can’t even remember a time where I had to switch it up during the appropriate season. I’ve waited seven years to figure this out, I don’t think I’m going to. Please tell me what you do to keep your house comfortable.