If I change my course details before the course starts will it affect my loans

It should be fine.

By repeating a year this year will be your gift year of funding.

The problem would be if you repeated the year without telling SFE - then the information from your university wouldn’t match your application and that would cause problems

I was literally told 3 days ago that i am repeating the year. would SFE understand my situation or?? I also changed my application details already like 2 days ago or yesterday

It should be fine. That's really common timing.