it doesn’t help that I’m not a morning person so it feels all weird anyway.
Yes, very much this!
it specifies not to mix it with anything but water and maybe the lemon flavor packet that is included on the side.
You might want to double-check with someone on the doctor's staff, if you can. I had one that specified that you could add sugar-free drink mixes, but at the time I had intolerance to artificial sweeteners (apparently often a side-effect of lactose intolerance). I explained to the nurse I spoke with that I couldn't have sugar-free drinks and they agreed that a drink mix with sugar should be fine. There may be some degree of latitude, but they just don't want people to take a mile for the inch they've been granted.
Either way, everyone agrees, mixing with cold water helps, drinking with a straw helps. And honestly, some of them aren't even that bad. They just taste like salt water (except the one I was given in the hospital - THAT was foul. Don't try to chug to just get it over with, though. That way led to vomiting for me. Yeurgh!)