Liability of the guarantor if the person who took a bank loan stops paying

Please help me.

I signed as a guarantor for my friend in her bank loan and they asked me for a security cheque.

My friend was on a partner visa and now she is cancelled and cannot pay anymore. I gave my cheque already to the bank and signed as guarantor.

Is it possible that the bank can give me a case if my cheque is zero?

My friend is still here on a visit visa now. She doesn't pay her loan anymore. I am scared that I have a travel ban and case now.

Please give me clarification.