I started my working life early in a supermarket as well. I think I learnt more there than I ever did at school. School was not my favorite place, more just something that needed to be done. I tried to get an apprenticeship in year 10 but had to wait until I finished year 11. I remember thinking I was finally free but Tafe once a week for a 4-year apprenticeship was pretty boring and painful too. At least during the apprentice training, I was getting paid!
Not finishing school has not impeded my progress through life one bit and I think it helped by getting out there and making my own way. Sure, I'll never be a surgeon or lawyer or some such thing, but I have a pretty nice life nonetheless and I don't have to thank school for it, I thank myself. Sounds much like your own situation I think.