Not necessarily.
Are you contrite?
Have you prayed for forgiveness? (re-established contact?)
Have your efforts to get to confession been sincere?
Saying that it has been “impossible”, that is, not possible at all, is a pretty big assertion especially given that it covers a “few months”.
I don’t say this as a judgement but only so that you may examine the term you use against the actual circumstances that prevented your going to confession when surely there have been at least 12 opportunities (since most parishes have confession at least once a week and assuming “few” means at least three).
That said, even if you are unable to get to confession at regular times, most priests will be happy to hear your confession by appointment. I strongly suggest you make that call and get to confession.
Again, please don’t take what I say as being judgemental, but merely “thought provoking”. Certainly I don’t know your circumstances or what you have had to deal with lately.
But back on topic of whether your prayers are effective, I cannot say. Assuming your contrition and your prayers for fogiveness, and sincere attempts to get to confession, then I would say that other prayers would have some efffect even if not “full effect” since you are no longer fully “turned away from God”
Peace
James