Lost Password, Cant Verify By Phone. Have New Phone Number

You can try the following Google page for Problems signing in to your account. This is a troubleshooting form, you will not actually be able to access your account but it is a way to isolate the possible solution.

By changing phones and forgetting your password, you have created a serious security conundrum. You really need to change the 2 step phone number first but you can't do that without the password.  Without the password you can't sign in even to have the code sent to the wrong phone number.

When you set up the gmail account, did you also link it to another email account?  Did you use a backup phone number for the 2 step process? Now you can see the importance.

Do you remember when you set up the 2 step process?  You were issued a series of emergency passcodes for the 2 step process just in case you didn't have phone access.  So if you didn't simply store those passcodes in your gmail but rather outside that account, you have a code you can use ONCE to access your account.  This allows you to bypass the phone issue until you can update but it still doesn't get you into the account to change your password. OR does it?  It will only work if you saved those numbers.

So what you can do is to go to the password assistance page, type in your email address and when you submit verify the captcha words, and select the way to get back into your account.

If you have those one time use codes you can then enter and reset your phone...and perhaps add some back-up information.

One more thing you can do on your computer is to go back in time/history to the day when you set up the gmail account to recover the password and security answer.  You can also do this for minutes before you initiated the 2 step process.

As a last suggestion, all of this security is there so that you won't find your email hacked. Consider a 2nd back-up account.