I am sorry to read about your frustrating experiences so far trying to get a flying job.
It’s true that your degree fees will be loaned to you, but that loan will not go away, it will have to be repaid starting when you get a job (as you correctly stated), whether the repayments will leave you with enough money to live comfortably is another matter.
Being an engineering student will not get you regular contact with the airline hirers and firers, and working as an engineer for an airline will not get you great access to the great and the good of the pilot community. If you can find employment as cabin crew you will be meeting and working with Captains and F/Os daily, networking and getting your face known. Some of those Captains will be senior management pilots (Chief Pilot etc) and links made with them are gold dust.
Even if the operator that you work for is not recruiting pilots, the pilots that you work with may well know other operators that are recruiting pilots and introduce you to the influential staff at that operator.
Honestly working with and being seen in a positive light by senior management pilots (like Mad Jock) will be worth more than any degree and you will actually be earning money while doing it.
Any benefit that an engineering degree will have on your CV will not be worth the effort and expense involved with the degree course.