I should have reported for my 90 days on the 2nd March, however my work visa expires on the 8th of March and i will be exiting the country. Do i have to notify anyone that my work has finished?, i.e immigration/work permit office

Also do i have to report for a final 90 days notice or will me exiting the country within the 7 days suffice?

Your employer will inform the employment department, and you have to go to immigration with a letter from your employer stating the date of termination. You will have to leave Thailand on that date or alternatively get a seven-day extension for 1,900 Baht.

You are staying longer than 90 days so should report.

If your last day of work is the same as the day your "visa" (permission to stay) ends, there is no need to visit immigration or labor. Both expire automatically.