Facebook and Instagram accounts have been hacked

Hello,

Can you please help me my account on Facebook? I have 2 accounts. I use only one which is hacked by someone who is now using my identity. I have reached out numerous times and I kept on trying in the URL. It goes too a completely different page. It's not the resl web page. Also, my Instagram, for the second time in a little over a year, has been hacked. I can't get into it! Someone has changed the email and phone number which I have never had before.

The last time my IG was hacked, someone had just changed the phone number. The Facebook I had for 7 years, had to be completely deleted as my ex had registered phone number. I took the back up in my email for 3 years and I had no idea. Please help!