Google Account Recovery: Old Number Verification

I am having a long-standing problem with my Google account that was previously linked to the mobile number 7725000***. For the last 4–5 years I have not been able to access this account properly, and now my mobile number has changed. I would like to use and recover this same Google account on my new number 6260913***. When I try to log in, the system directs me to the old number, so I cannot receive the verification codes and I get stuck in the process. I have already tried the “Forgot password” option, but because the number 7725000*** is no longer with me, I cannot complete the recovery steps and I remain locked out of my own account. I request Google to help me recover this Google account and update the linked phone number from 7725000*** to my current number 6260913*** or provide any alternative secure way so that I can regain access to my account.