how do I de-activate my current account?
because I only have 1 mobile number and email to create another new account.
First of all, why do you need a second account? Maybe the reason you have for making a new account isn't a good one.
Secondly, i'd urge you to use a "decent" wallet, and stay away from online wallets.
Thirth, if memory serves me correctly, you don't have to couple a phone number to a blockchain wallet if you don't want to (i can be wrong tough)... If you're using your phone for 2FA, you can just as well use an authenticator app instead.