If someone curses God out of anger...will God forgive them?

I webt through a lot in life, and on the verge of commiting suicide I cursed God using profane language...because at the time I didn't know any better because I thought if there were a God he wouldn't let me go through all of this and not help me at that time. Since then I have gotten saved and I feel terribly wrong about it...is that considered blamsphey? And unforgivable?