Feeling sorry for my self but can't shake this feeling 😔

I am 17 and have a 2 year old and one on the way I love my kids beyond life it's self but I wish I would of waited and got my life together before I started a family. I am happily in love with the father of my children but I wish him and I could of experienced life adventures before having kids. He has his high school diploma and has a great job with retirement and everything and I just feel like a piece of shit because I didn't even finish middle school and I regret it so much! I have been trying to get my GED but the test is so hard I can not pass it. I feel so depressed and stupid! I want to go to school and become something great for myself and my family but I just feel like it will never happen. I'm feeling sorry for myself and I hate it and can't shake this feeling. Anyone have any advice on how to get motivated?Â