A little discouraged...

EverSinging

This sounds like a complicated family dynamic.

Making the time to workout when you work full time is hard enough. It's harder when you're a parent. It's even harder when you're a single parent (I'm in the that club too!). You could do the reverse like I did for years, and simply not do it (I joke that it only took me five years to lose my baby weight...because I didn't try until he was four). But then how are you serving your child? Are you teaching him bad habits for life? Eat, don't exercise, don't ever take care of yourself? That's not a lesson to teach. So no, we have to find a balance. You can't magically "find" time to workout, because we all have the save amount of time in the day. So, in order to exercise, we have to give up something else, whether it's a little sleep, or a little time with family or friends, whatever. Something else goes. That's just life. But you are definitely not doing your child a disservice by prioritizing health. That is a lesson he will learn and see from a very young age, and that is not a bad thing!

Maybe you can adjust your workouts and what you do. It sounds like you need to find someone else to help with childcare, or perhaps, find a gym with childcare available there. You can't make your sister help. If she doesn't want to, then she doesn't. I tend to do my fitness free, so I incorporate my little guy in it. Running stroller (which I hate...) when he was younger. Then as he got older, he biked while I jogged. You just have to find a balance that works for you.