Did you just "update" your Apple ID from hotmail to gmail? To me it looks like that instead of actually updating your Apple ID you instead created a brand new account. To update apps you must be using the same account that you used to purchase the apps originally. If this is indeed what you did you are now in a bit of a mess because if you try to do this correctly now, Apple will not let you re-use the gmail address. You will now need to update to an email address that Apple has not seen before, or go through a pretty complicated and slow process of transferring email addresses between accounts.
It would help if we were clear as to exactly what you did.
My understanding from what you have written so far is this is what you should have done --> The support article Change your Apple Account primary email address - Apple Support outlines various methods for changing the email address (Apple ID) you use for your Apple Account while retaining everything in your account.
This is the slow process of trying to reuse an email address you have used with a different account.
Change your Apple Account primary email address - Apple Support
- If you remove an email address that isn’t an iCloud email address from your Apple Account, it can’t be associated with another Apple Account for 30 days for security reasons. After removing an email address from your account, notify anyone who might contact you on Messages, FaceTime, or other Apple apps using that Apple Account email address. After 30 days, another user might be able to associate that email address with an Apple Account for Messages, FaceTime, and more.