This is absurd. Child support is based on income. He makes more, so he pays more. That's just fair. Also, you stayed home to allow him to work. You should at the very least ask for alimony for the amount of years that you stayed home, so you can get back on your feet with your own education and career. Any less and you are short hanging yourself and your kids.
As for visitation, it is his responsibility to find a suitable home for his children, not yours. He can afford more than a 1 bedroom on his income. That's ridiculous.
The best investment you can make with your savings is to get child support now, while you can afford an attorney. If you spend that savings now, trying to protect your XH's "feelings," you will find it very difficult to take him to court later (you won't have the retainer, etc.)
What you describe sounds sustainable NOW, but will it be in the 3 years? Since your children will still be very much your responsibility still in 3 years, I'd focus on the child support in writing as an insurance plan for the sake of your kids.
As an aside, I think a lot of men feel it's "unfair" to pay child support when they don't have the kids most or a lot of the time. Of course the women who are being always "on call" and the ones monitoring homework each night and picking up the kids from games/friends/lessons/school, also feel it's "unfair" that they are only getting 50% of their children's expenses while doing some 90% (or more) of the childrearing work. I say that not to validate his feelings but to point out that "fairness" is not a good measure... I'd recommend thinking about "what's best for our kids?" as a better standard.