Cindy,
you sound like an "overresponsible" to me which can do nothing but lead to more frustration and helplessness. Your heart is in the right place but you need help. A network of people and resources is vital to get through this. The American Cancer Society can provide rides to treatment and many churches can help with respite care and other issues. Friends and family need to know your plight so that they can GIFT you with their help also. Why can't other soccer moms step up and pick up your sons and drive them home? Why can't other mom's help get your boys to scouts? Surely your husband has some buddies which could come over and keep him company while you have some time to yourself. Talk to the hospital social worker about other resources and support groups that can assist you.

When I was caregiving my dad years ago I went through tremendous guilt wondering whether I did enough and after 10 grand of therapy later, he (the therapist) set me free by telling me that it wasn't my responsibility to personally DO everything - just to make sure it gets done.

Speaking from personal experience (as in 10 years in AA) I can also tell you that never once have I solved a problem while drunk (and believe me for over 40 years I tried).