Is my prayer valid after I performed ablution for Fajr prayer, then felt some wetness and temptation from Satan, so I said, "Religion is ease; Allah does not burden a soul beyond its capacity," and then prayed?

It is clear that the questioner is afflicted with waswasah (obsessive whispering), and its cure is to turn away from it and ignore it. The correct approach is to build upon the certainty of remaining in a state of purity (tahara), as its invalidation should only be determined by firm certainty. When in doubt, one must proceed with the act of worship and pay no heed to the doubts. If the questioner is certain of the emission of vaginal discharge, she must perform wudu' (ablution) but is not required to perform istinja' (washing the private parts), because vaginal discharge is considered pure according to the preponderant opinion.