Forgot Gmail password

Hello,


I have forgot my gmail id password and I am also not able to access into my recovery gmail id . I have recovery phone number , two factor authentication number and date of creation of this account . I tried to recover my account by these information but that was not satisfactory for Google to recover my account . I tried so many times to recover my password but every time I got failed . I have access in my account in my phone only but I have to change my mobile handset so I need to reset my password . This gmail id is very important for me because all important data are in it . I can'nt lose access in it . But now I don't know how I will recover my account or reset it's password .Please help me in this issue .