You are most certainly not worthless. Your feelings on this will take time to resolve. Just remember that this situation is only temporary, you aren’t stuck for

You are most certainly not worthless. Your feelings on this will take time to resolve. Just remember that this situation is only temporary, you aren’t stuck for life. Many of us have been, are currently or will be in the same position. New opportunities will arise, I guarantee it. In the mean time, do whatever you can to renegotiate the on-call duty if you are the only one handling it. Since they are entirely reliant on you here, you have quite a bit of leverage.