If you're running out of water, you need to make sure you stock up as much as possible before leaving, which requires you to have NOT consumed all of the non-infinite water before you leave (from the Extract Water action). If you're running out of air then you just need to use the Fill Air Tank action more often/earlier.
If you need more advice, I recommend joining the Discord. There's a lot of people active on there, including several who are trying to optimise speed runs.