I cannot tell you that it will be great.
BUT you will be a lot more great than you think you will be.
Your children will not suffer, because they will understand and you will explain it to them, plus you will also be so much more fun for a shorter amount of time each day, and they are growing up, so... they will cope.
You can still do all the things you did before, and perhaps more. You will still HAVE to do all the things you did before, perhaps less due to simply being out of the house.
Try it. You will be great. You may need to tweak things as you go, but it will be fine.
I was 8 years a SAHM, loved it actually... I then worked full time, the money wasn't enough to enhance anything, I now work part time, I literally earn about £200 per month after childcare, petrol etc., but I LOVE IT.
Nothing is forever, you can assess problems as they arise, and mostly you can overcome them. Good luck!