Can a badly cracked iPhone screen be repaired?

We, just users like you, cannot diagnose that kind of issue remotely, sorry, but it sounds like the whole structure of your iPhone is compromised (bent). Should be this case, I do not think your screen can be replaced, but, to be sure, I suggest that you make an appointment (*) and have your device inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> https://locate.apple.com/choose-country-region . After checking it out, they'll give you all the available options.

Regards

Giulio

(*) You can do it:

• Online:--> Genius Bar Reservation and Apple Support Options - Apple;
• Contacting a local Apple Store or AASP among the list provided above;
• Using the "Apple Store" app, available and downloadable from AppStore.

No.

It will have to be replaced.