Time loop paradox in The Flash

In season 1, episode 15 (Out of Time), we see a time loop in the end.

Assuming the timeline when the episode started to be x, in the end, we get to timeline x+1.

So, does Barry retain his consciousness of timeline x when in timeline x+1? If yes, then did Barry of timeline x have the memories of timeline x-1 when he saw a speed mirage? If so, why didn't he stop the events of timeline x from happening?