Awareness and prayer are the first steps because God does not want us rushing in all directions.
You mention that your financial situation is the only link keeping you from resigning at this point. Please do not imagine that this is unusual. Everywhere we turn today, we receive the message that families cannot live off one income. To an extent, this is quite true---one-income families usually cannot live the way two-income families do. This does not mean that one-income families are depriving their children. Sometimes we can live better off one-income, but it is not easy, and you will probably be criticized for perceived financial harms to your children.
Changing the family's financial situation is scary, and it requires some sacrifice. Many years ago, I left a well-paying position in insurance, and we went through some rough times because of that. We weren't planning to home school, but we did not like the day care options available. Some home schoolers have small home businesses, which help increase the family income. However, even with both parents working full-time, families have no guarantee that they will not hit very difficult financial times. I think the key is not being afraid of financial setbacks, or at least, to realize that they may or may not come, and that we have no control over many of them. You may gain some peace of mind if you have some savings in the bank for emergencies, but the best peace of mind comes from a deep trust in God.
You may experience some financial guilt because you could be making X amount of dollars. That is misplaced guilt. You need to focus on what you are saving the family. You have the time to shop for deals, to negotiate, and to review your finances instead of resorting to convenience purchases because you simply do not have the time to explore and think through choices when both parents work.
Moreover, husbands are not usually as excited about home schooling as mothers are, unless the husbands are working in the educational field! Many home schoolers I knew back in the early 90's were teachers who understand the educational system and opted out of it for their children. I noticed that the male teachers were quite gung-ho for home schooling when sometimes the mothers had to be convinced if the mothers had not been teachers.
While you certainly want your husband's support, some mothers home school without much support. Their husbands are okay with home schooling, but definitely not excited about it. The fathers are not there to see the difference, but you are, and the difference is exciting. That may be your situation, and you will simply have to accept it. (The fathers get hints every now and then from total strangers who will remark about the children's intelligent and courteous behavior.)
Perhaps it would help if you ask your husband about a trial period of a year or two. You need to give home schooling at least a year, but if finances make it truly impossible, you will be able to return to work. I'm not sure if you are in an area that has many Catholic schools, but I have noticed that the schools in my city seem to have a great deal of turnover with teachers and principals. If that is the situation in your area, then you could easily move back in to another position if necessary.
May God smile upon your family and grant you peace.