I would not recommend a Magickal solution as the first resort for a problem which is not magickal in nature. This is a human issue, not a Magickal issue.
The first step is to talk to him, openly and without ego. Discuss what you both want, and what you expect will happen when separate financial stability becomes a reality. The best thing you can do is explain your feelings, express your continued love, and show your desire to keep your family together. It's wise and mature of you not to want to force anything.
If, after that, you find that your desires don't align and compromise isn't possible, then you can still have a serious talk about your future as a family, since, if anything, the two of you are likely to be brought together over your son for the next fourteen years or more.
The Universe doesn't always give us what we want, but most often, it DOES give us what we need.