Migating my site

hello! recently one of my websites moved to another server… (the server admin asked me to send the files so he can transfer them)

when the website was up and running again i couldn’t login to my admin account, also i had an inbox telling that password changed for user:admin… but i’ve never been notified about this change, furthermore my email disconnected from the user:admin…

as a result i have no idea about who is running this site and i’ve never had a notice.

is there a possibility that the website is hacked?

pls any ideas will help

***i informed the server but no response yet

thank you!