Webforum has been threatened with a libel suit

I have created a webforum for discussion of a certain boarding school. The school is located in Utah. I live in Illinois.

The boarding school has sent me a letter by certified mail, stating that:

''Statements on your website are not accurate... Some of the statements [on your website] appear to cross the line into slander and libel. We ask that you remove the website immediately so the leval remedies available to us do not need to be pursued any further.''

I do not want to remove the webforum, because ex students have been stating on the webforum that they were abused by staff at this school, and I have reasonable cause to believe them.

However, I do not want to lose my house over legal fees arising from a SLAPP suit.

Can someone please give me some advice? I don't have the money to pay a lawyer a multi thousand dollar retainer, on top of hundred(s) of dollars an hour to advise me.

Thank you very much.