Get UK Law Questions Answered by Verified Experts
I'm afraid it's bad news, you will not be released from your obligations under the guarantee. Indeed this is the point of having a guarantor, someone other than the person taking the loan will be responsible for the monies owed as a result of that persons default.
You should check the guarantee to make sure all the formalities (ie. signatures/witnesses/) are all present and correct just to make sure it was properly exectued.
If you cancel your direct debit with the bank they will just sue you for the money (and the costs of sueing you), you should speak to your daughter's boyfriend to see if he can help in assisting you with the payments.
I'm sorry I don't have better news for you. If this has been useful please kindly click accept so that I can be rewarded for my time. It will be gratefully received and you will be free to ask follow-up questions.