I agree 100% with momof3. We just finished our 4th year of homeschool and I still feel like I'm brand new to everything. I wish I wouldn't have tried to duplicate public school at home. It was so stressful and the complete opposite of the reason I wanted to homeschool in the first place. I was so afraid of "messing up" my children's education that I went way overboard and sucked out all the fun of homeschooling. Honestly, I still have those fears but I've learned to relax a bit and that has helped so much. My son will be going into high school next year and that brings up a whole new set of fears since everything from now on will be on his transcript. I constantly have to remember why we started homeschool in the first place and that helps.
I highly recommend writing out a mission statement. When those doubts start to creep in (and they will) you can look back at your mission statement and remember why you started homeschooling.
Personally, God was our main reason to homeschool and I printed out scriptures to remind me I'm following His calling and I reread those and pray over them when needed. I'm so glad I took the time to research and print out the scriptures.
Just know, you will have doubts no matter how long you homeschool. It's normal but don't let those doubts take away the fun and experience of getting to see your kids thrive at home with you. God has qualified all moms to nurture and educate children at home. He wants children to be in this world but not of this world and we are the ones to do it.
Sorry, I kinda got off topic but I just want to encourage all moms that read this, you can do it and no one can love your children like you do.