Much of what you have said there has some ambiguity, which might be why you are having trouble communicating with support.
By "I point the DNS to cloudflare." do you mean that the nameservers for the domain are pointed to cloudflares nameservers? That's how I generally read what you wrote. That would be a setup that support doesn't deal with often, but should be aware of. What they deal with and are most familiar with is cloudflare via the dreamhost panel. It's also one of several different possibilities for domains in general but the only one that's particularly logical in the case of cloudlfare.
If that's the case what you should need to do is lookup the IP that Dreamhost assigned to the domain. You can do that by clicking DNS in the dreamhost panel for the domain that has DNS nameservers pointed elsewhere. Dreamhost still generates DNS records on dreamhost nameservers, but since the domains nameservers are pointed elsewhere the dreamhost entries won't be exposed anywhere except internally at dreamhost.
If that's the case get the A-Record and head over to cloudflare to replace the old hosting providers IP with the new one from dreamhost, that you just looked up.