I do not believe that I have ever felt unequivocally positive prior to a session of exercise. Even if I am mostly looking forward to it, there is always an underlying dread of pain.
If I had to wait for the unequivocal feeling of wanting to run (or lift or whatever), I would never do it.
And so it is a good thing that mood follows action. Once the running shoes are on and the warm-up is over, my feeling always improves.
I think the same can be true of showing up to a habit of prayer, meditation, any interior practice… or anything representing generosity, really… Even that stack of dishes, paper work, or emails…
Beginning is the first step toward a breakthrough.