Yep, I'll endorse the value of Ratbag Drew and co.
What I find difficult is choosing the right targets. A good week with obvious improvement will get me all excited, and tends to be followed by a disappointing one, in which I cannot keep up the progress, or worse, injury.
Be kind and encouraging to yourself: celebrate the good bits, and if bad days happen don't scourge yourself but trust it will get better again. It works best for me if I retreat a step or two, or try something different. So if my "usual" six mile route seems suddenly difficult one day, I might try it next time writing in more walking breaks than usual, and allowing myself, if I feel really well in the last 2M, to play about with the pace.
Two steps forward, and, if necessary, one step back, will still make progress.
(In trying to build up time on the road and distance, never underestimate the value of early, frequent, scheduled walking breaks. Even if somebody has already said that, it is worth saying again.)
Above all, enjoy it. Marj