You ripped off its toe while helping it shed? It's not entirely clear if that's what happened.
Unless you know that the shedding is problematic, you should never help them. When it starts to bug them, they'll rub themselves up against anything abrasive they can find. That way, you're giving control of shedding to them. If they really need help, soak them ahead of time to loosen everything up.
The fact that he lost a toe sucks, but providing you've kept it clean, it shouldn't be life threatening. Take it to a vet if you want to cover all your bases, but I've seen some pretty rough looking geckos that got into fights en-route (my dad sold reptiles wholesale), and they were otherwise perfectly healthy.
I'll say it again. DO NOT help them shed by pulling at the loose skin. Give him a piece of wood to run against, and a good soak, but don't manually pull the skin off.
If it's been on for awhile (> ~3 weeks), there is solution you can buy from pet stores that helps loosen sheds.
If you're worried still after that, take him to a vet. Given he's lost a toe, that wouldn't be a terrible idea anyways as a precautionary measure.