If you and your husband carry an individual policy, you're right, you can't change due to pre-existing conditions (diabetes is not likely to magically disappear). However, if your husband is employed by a company, their insurance plan cannot deny you coverage for a pre-existing condition. If you and your husband are relatively healthy, and you have to stay in Blue Cross, try enrolling in a plan with low premiums and a high deductible (which hopefully you'll never have to meet), i.e., a catastrophic coverage plan. That may qualify you to open a health savings account, which your husband's employer may contribute to. That way, if you have out-of-network costs or any other healthcare-related expenses, at least it comes out of pre-taxed dollars.
You're in a tough situation. I know people who are working full-time just for the insurance coverage, not for the minimum wage. Good luck.