I stand as a guarantor for my friend. Am I liable for his bank loan?

I kindly require legal advice.

I have a close family member who has multiple loans in the amount of BD 19,000. He was unemployed and the banks threatened him with legal action. He came to me and confirmed he is set to start at a new job and will be able to pay for his loans, BUT needed me to sign as his guarantor so the banks would refinance his loans. Due to the close relation, I agreed.

I later learned he never paid a single instalment and also resigned from his job. Now the banks have taken legal action against me. It seems he is unwilling to cooperate with the banks.

How can I get out of this mess? A response is highly appreciated.