i can't really tell you about whether or not university will help or not, because i haven't been yet. but i think what you're studying is really admirable and i wish the best for you and your child(ren).
when it comes to confidence in yourself, i think that while external factors definitely help or hinder growth, it also really depends on what steps you take personally to improve it. maybe in university there would be more opportunities for group work and social events where you can push yourself out of your comfort zone, or you may find uni even more isolating if it means you'd have less time for current friends and not enough time to make new ones. i can't say for sure because i don't know your situation as well as you do.
if you struggle with feeling anxious about how uni will impact you and your confidence, and you want to understand more about how you feel, you can try sorting out any worries you have.
for example, one thing you could do is write down a little personal list of things you hope will happen or dread happening at uni. they can be social, academic, work-related, whatever. then rate them based on how likely you think they are to happen, and how you think they would affect your confidence. then give it a think over, and most likely you'll conclude that most things at uni won't have a really big affect on your confidence. instead, it's something to develop internally and work on regardless of whether or not you're at uni. and i hope writing down all the things you're hopeful about uni will encourage you to attend with an optimistic outlook and a determination to develop yourself, like a fresh start.
sorry if that doesn't make much sense, but i hope it helps somewhat xx