You are already heading down the road of disappointing everyone when you ultimately collapse and burnout... You must see this or you wouldn't be looking for a way to lessen your work load.
I was thinking the same thing, but didn't want to say it. People almost always err when they are exhausted.
It starts with a cup of coffee slipping out of your hand, falling on your toe and breaking it, hot water splashing on the cat who jumps up on the curtains and rips them to shreds. Gets the dog barking. You cut yourself picking up the broken pieces, spill blood all over the kitchen counter, then a neighbor walks in and accuses you of attempted murder by mug shard. And all you wanted was a nap, or some caffeine to keep you functional.
Disappointing people can be tiring, and more work in itself. But facing the drain of doing that with resistance, shows you really are tired.
There are some other options. You can get help. I mean, more leaders. A few older kids, or parents to help out, or a young couple new at church. Rotate helpers, so that members of the church get personally involved with the youth... The Youth becomes less of an isolated category.
Turning down the opportunity can give people a negative impression of you, and set you back in church-related social progress, whatever that might mean. But it could get worse if you are overloaded and unable to keep up.
The more responsibility we take on, the more it grows. Imagine you encourage a visitor to come to meetings. They tell you about a drug addiction that seems to be forming. The parents hold you responsible for fixing their teen, and the law holds you responsible with the information. A tiny act of generosity turns into a consuming responsibility.
All this aside, I think we need service projects like this to keep our own spirituality alive. I don't think that stepping out of it will improve your spiritual life. It's like the concept of teaching so we learn... holding a responsibility in our minds that keeps us channeled into staying current and knowledgeable. So yes, maybe you're in a low spot and could be a bad influence, but it's also important that kids see weakness as a real part of life and Christianity. Humility can mix with power.
School and full time work are already a lot to take on. But find creative ways to manage boundaries in your life. Use your group for one of your papers. Train youth to take on responsibilities. Find a parent coordinator who will make phone calls and even arrange for helpers to rotate at meetings.
Ask the students to rotate leading the teachings. They can do it, and will gain from the challenge... owning their faith more.
A manager or leader is in charge, but eventually they learn that they are delegators, not just doers. You are a delegator, and can raise up the people under you, to be strong leaders and doers. It takes time, but it can happen, and eventually the burden will not all be on you.