Need help with Apple ID login for iCloud/MobileMe to move Calendar.

Despite the multiple warnings from Apple that MobileMe would be shutting down on June 30 & that I needed to migrate my "stuff," I didn't realize that my iCal calendar on my Mac & iOS devices (iPhone, iPad) was through my MobileMe account (@me.com login) and not my "main" Apple ID account (which is a Gmail login), so I didn't bother doing anything to migrate my "stuff" because I hardly ever used my MobileMe account, or so I thought. That said, my life revolves around my iCal calendar-- can't live without it! Two days ago I started getting a pop-up message on my Mac that says "iCal can’t log in to your “____@me.com” account because your password may be incorrect." It was while I went through Preferences to fix this that I realized my MobileMe account was the master one for iCal! I know that my password was correct, but I'm guessing it has something to do with the fact that MobileMe is now shut down that caused the pop-up in the first place. Meanwhile, my calendars are not syncing between my devices, which is something I'd like to resolve ASAP!

I'd like to push everything over to iCloud, but I noticed that for some (dumb) reason, I used my MobileMe account login for iCloud as well! Is there any way to merge or replace my MobileMe account with my Gmail Apple ID account so that my iCloud is no longer tied to MobileMe, since that program is now defunct? If not, at the very least, any help you could provide on how to transfer my calendar to the Cloud would be much appreciated! Thank you! 🙂