Withdrawal of Application for SSI

I was recently approved for disability. At the time I filed my disability application, I also filed an SSI app although I never received any supplemental income. I called and asked them to withdraw my SSI App...I don't qualify for it and I don't want it to hold up my payments. They sent me a form to withdraw the SSI app and also advised me that this will affect my ability to get Medicaid through SSI. I really need to get on Medicaid which I qualify for, but if I sign the withdrawal form it sounds like I might not get it. This is Kansas Medicaid. Do you know anything about this or can you recommend what I should do to be able to get Medicaid, plus my monthly benefits and back pay? Thank you, Julie