Oh, Dear, do I remember this so, so well. I was so panicked before my first chemo. How could I go? I raced to the board and posted a message very similar to the one you just wrote. I don't have words to describe the terror I felt. Retrospectively, I guess it was a terror that was out of perspective to the actual event.
I called my brother in VT who serves as my brother/mother/father/therapist because I have pretty FU'd support system husband wise, and a long, complicated dysfunctional family story. Anyway, I called him and said I wasn't brave enough to go in for chemo. He replied, "well, what would being brave for chemo look like?". Me: I don't know. My brother: Maybe it would just look like putting one foot in front of the other, then going through the door, then sitting in the chair. Me (crying): OK, I think I can do that. But then what? My brother: B-R-E-A-T-H-E and know that you will know exactly what to do, one breath at a time (or something like that).
Anyway, that worked for me. There is, in fact, no prescribed way to do it, but putting one foot in front of the other seems like fantastic advice. I was far more scared of chemo than surgery, but as many on the board will tell you (they told me) it's not as bad as you imagine. Your partner is lucky to have you. The biggest help is to have someone there, as far as I'm concerned. I slept through a lot of my three rounds of chemo, but it was the best to know that my son was there with me.
Good luck tomorrow. I hope, and expect, it will be much easier than you are thinking tonight. Sending you lots and lots of hugs.
58 yo Type1 DM 48 years
12/09 Stage IV 2/22 nodes + liver met, colon resec
3 tx FOLFIRI, liver resec 4/10
9/10 6 mos off chemo, Neg PET&CTC CEA nl
2/11 finished total 10 rounds chemo
9/13 ^17th clean PET/CT NED for now