I had a thought that Id like to share.
Some time ago when I was becoming frum, I had been keeping Shabbos for about year and it was really easy, never tempted to break at all. However avfter about a year I started to feel sick about the idea of keeping Shabbos and suddenly didnt want to anymore! My Rabbi explained to me that the first year was a gift from Hashem and once I was ready to try it myself and actually work for the Shabbos it woould become harder. So I started learning about Shabbos and going to shul and that was enough. He said to me that I will always come accross this in life, things being easy to start, then once Hashem sees that I can do it myself He lets us earn what we had.
Perhapds the same is true here, I had 90 days - easy. Now! I cant get 3! not even 3! so now if Hashem feels that I'm ready to start fighting this (of ourse I still need syata D'shmaya, not saying not, but before it was me at all, just a taste of what could be) then who am I to disagree! Hashem, I cant do this without you though! Please help me to earn this purity.