God is merciful. More merciful than we can understand. I don't think he has a limit on how many times you can return to him.
If you didn't desire God's mercy and grace, I'd be concerned for you. But since you do, my only concern is when are you going to realize that He loves you and has forgiven you? How much will you suffer believing that you've done too much for Him to love you?
Is this how you feel?
I cried out to God for help;
I cried out to God to hear me.
When I was in distress, I sought the Lord;
at night I stretched out untiring hands
and my soul refused to be comforted.
I remembered you, O God, and I groaned;
I mused, and my spirit grew faint.
You kept my eyes from closing; I was too troubled to speak.
I thought about the former days, the years of long ago;
I remembered my songs in the night.
My heart mused and my spirit inquired:
Will the Lord reject forever?
Will he never show his favor again?
Has his unfailing love vanished forever?
Has his promise failed for all time?
Has God forgotten to be merciful?
Has he in anger withheld his compassion?
I think the writer of this found out that the answer to these questions was no.
Put your eyes on Christ, not your sin.
“Come now, let us reason together, says the LORD: though your sins are like scarlet, they shall be as white as snow; though they are red like crimson, they shall become like wool.
It's Christ's sufferings that made that so. Let's praise him for his mercy and grace all the days of our lives and quit with the continual digging up of what we've done and the focus even on current sins. Me included, cause I do this stuff too.
You better believe all this because God had me stay up way too late typing all this. :)