"There's no way I could have gone on for as long as I have if I'd stopped feeling for my donors every step of the way. " Because I felt for my donors during this whole process, I was able to continue for as long as I have. (=all this time) Is that better?

Either you have copied the quote incorrectly, or it is poorly written. To make sense (grammatically) it should be: "There is no way I could HAVE gone on for as long as I have if I'd stopPED feeling for my donors every step of the way. " In answer to your first question "..as long as I have" means for the period - the length of time that I have gone on (doing whatever it is the author has been doing). As for the rest I don't understand as I don't have any context - what sort of donors? blood donors? political donation donors?? What 'way' are they on? There isn't enough context to make sense of it.

we need to know what was being donated, and who were the donors. There are two sentences (or two clauses) in your text. It needs a period or full stop. Or maybe a comma. 1) with period/full-stop "There's no way I could have gone on for as long as I have. If I'd stopped feeling for my donors every step of the way. " 2) with a comma "There's no way I could have gone on for as long as I have, if I'd stopped feeling for my donors every step of the way. " It looks like somebody is being donated an organ or something medical? The recipient was able to carry on, because they felt something for the donor. However the same could apply to any recipient of any kind/type of donation. An alcoholic could receive donations and fell for their donors. The sentence does not give us enough context to work with.

Needs more context

Sorry, I typed it wrong. Now it's the edited version,