Can i get some help? it would be greatly appreciated.?

im a kid who has had a bad childhood, i wasn't a very good kid. And to this day i have gotten my act together a little bit. im 16. I have Religious views, and my whole life i have disappointed myself, and others, but the person who i didn't want to disappoint is God. And i have disappointed him. I have blasphemous thoughts (which i don't mean), the things i did as a kid probably disappoint him too. I,am usually a quitter, but i,m not going to let go on something so big and important to me. But will God forgive me for all the bad things I do? This has really brought me down. I don't know if i need more self-confidence, but whatever i need; i need it alot.