I'll help you step by step: Please follow all of the steps given below.
A. First of all, please check your webmails:
Click the link and check if you're able to login into your gmail webmail account or not.
B. If you're not able to login, please try to reset your gmail password ***** the link below:
Choose I don't know Password. Type in your Email Address. Click Continue.
Follow on-screen instructions to reset your account password.
C. If not fixed:
Click the link given here:
Choose I don't know Password. Type in your Email Address. Click Continue. Enter the last password ***** remember.
Check if it provide you options to reset your password.
Else, please click "I don't know" under Enter the last password ***** remember option.
And then click "I can't access my phone".
And provide them as much information you can.
Be sure to fill out the form completely by providing your best guess to all
Provide you alternate email address as contact email address. Gmail team will get back to you on this email address in 12-24 hours.
Please reply back to me at the box given below.
Please rate my service by choosing stars and the click Submit.
Thank you very much,