Q: is there anyone to merge 2 icloud accounts into one cloud

You could migrate the data from one account and merge it with the data in another account but that would not do anything about your music using too much space on your phone.  The only way to solve that is do delete some of it off your phone, or subscribe to iTunes Match so you could access your music library from iCloud without having to download your entire library to your phone in advance.  Music stored in iCloud does not use any of your personal iCloud account storage.

Start by saving any photo stream photos that you want to keep to your camera roll (unless already there) by opening your my photo stream album, tapping Select, tapping the photos, tap the share icon (box with upward facing arrow), then tapping Save to Camera Roll.  If you are syncing notes with iCloud that you want to keep, you'll need to open each of your notes and email them to yourself so you can later copy and paste the text into new notes created in your new account.  Then go to Settings>iCloud, tap Delete Account, provide the password to turn off Find My iDevice and choose Keep on My iDevice when prompted.  Then sign sign into the other account and choose Merge to upload the data and merge it with the data that is already there.

That has nothing to do with your iCloud account.  That's based on the Apple ID you are signed into in Settings>iTunes & App store on your device (which may be the same as the ID you use for iCloud, but that's just a coincidence).  The problem is that once you have access purchased media such as your music from iTunes in the Cloud, your device is associated with the ID you are signed in with and cannot be switched to another ID for 90 days (see http://support.apple.com/kb/HT4627).

Also, you cannot move music purchased from one ID to another.  You'll have to import the purchased music to your iTunes library by connecting your devices to your computer, opening iTunes, then going to File>Devices>Transfer Purchases.  Once they are in your iTunes library, you can sync all your music to either device.