Also don’t blame yourself, you’re doing the best of your ability!
I agree. You are doing your best. And it is clear you love your kids. Try alternative approaches. 1 of my kids loved the leapfrog videos for letters and reading but the other needed play dough, sand and stamp markers.
It’s never too late to start teaching them the basics! I work at an elementary school and believe me, some don’t know their abc’s either. Start introducing them a letter at a time. Learning doesn’t need to be the conventional way with pencil and paper, they can use play doh or write in sand. It can be interactive and fun! 💜