Just got approved for SSI and got a back payment check that is over the max I can have... Help?

So I just got approved for SSI, and I received a back payment check of over $3,000. This is great for me since there are lots of things I need, but the problem is that I don't have a bank account at the moment, and when I called them to ask about that, they weren't exactly very clear on how this can or can't affect my benefits when opening a bank account...

So the person on the phone explained that it would affect my benefits unless I opened a "Dedicated" account for the back pay, and a normal savings/checking to have direct deposit of my normal monthly pay. After getting off the phone with them, I looked up what that was, because I had never heard of it before, and it's an account for children under 18 with SSI...? I'm 37? I looked at the possible other accounts, and all of them seem to have restrictions on them that will cause issues, or I don't qualify for them. What exactly am I supposed to do about this?