be running on fumes

To be continuing to operate with no or very little enthusiasm, energy, or resources left. I've been painting the house for four hours every night after work, and I am seriously running on fumes at this point. We were running on fumes by the time our team made it to the championship round. After I came down with a nasty cold, I was running on fumes the last few weeks of school. I'm so glad summer break is here!