I left my job when my son was around 2 and 1/2. It was a hard decision because my husband and I relied on our two salaries to get by. I also had health benefits, my husband's job did not.
We made the decision for me to stay at home . We cut expenses in food, gas, and childcare. We also saved money throughout the time that I was working so that once I stopped, that money could be used for health insurance/medical needs. I would recommend you save for this, as this definetly was very helpful to us.
My husband took on two jobs and we were able to make it work. My old job also was very helpful in giving me some paperwork that I could do at home for them. So, I did get some money each month. My husband also started taking courses/trainings in his field to advance in his career.
My son is now 8, and my husband is doing well in his field. I am still a stay at home mom, and have taken to writing, painting, and photography. I am selling my work, and enjoying it.
I don't think we would be at this point if we didn't sacrifice for our family a couple years ago. When you have that desire to do something, and just know that it is the right thing to do, never go against that. It serves a greater purpose in the long run. I know it does for us.