When we wish for something, affirm something or pray for something, we find a spot when we are most fervent and then comes one thought that brings it all down - one that says it won't happen. All the energy you built up creating your edifice comes crashing down and we don't have the patience to build it again. So we leave it as it is, rubble.
But I feel its part of the process. Ask, wish, affirm, pray, visualise - and stay as long. Then, since we are unused to it, the messy thought will come and destroy it.
But don't leave it there. Hold your original thought. Leave that exchange between you and the devil on a slightly plus note. Every time it crashes, end the exchange with one positive, final visual or thought of what you want and hold on to it. The last thought should belong to you, what you want.
And when we do that on a regular basis, the negative thoughts reduce slowly. Whatever happens, we will hold our reality. I suspect that things may turn out differently. It did for me several times.
Worth a try.