Hi Behizz,
The account that the service uses needs to be in the Local Administrators group of the server that you are running it on, we use most of time sp_farm so add it in local admin group.
After adding the account to the Local Admins group of the server, restart the Sharepoint Timer Service. Then try and start the User Profile Synchronization Service again
If still it is not fix the issue I would prefer to delete UPS and create it again,
For deleting you need to stop First of all to the User Profile Synchronization Service you can use the powershell Get-spserviceinstance to get alls.
This will list out all of the services on your SharePoint Server with their associated GUIDs. Copy the GUID for the User Profile Synchronization
Service.
Then run the following command to stop the User Profile Synchronization Service.
Stop-spserviceinstance <GUID>