You have to consider how you would earn your living should aviation not work out for you - which it doesn't for quite a few! if you are content to settle for a non-professional (what used to be called 'blue collar') occupation, then there isn't much justification for a degree. If, on the other hand, you would like to be eligible for the more interesting (not necessarily the best-paying!) occupations in our society, then a degree is essential.
Some would suggest that you're better off doing a plumber's or bricklayer's course if flying doesn't work out. I disagree. Most people with sufficient intelligence to consider flying would be driven out of their minds by the boredom and frustration of a manual job - but you might earn more money for a while! However, I don't know many bricklayers or plumbers whose earning potential after, say, 20 years, equals that of most professions.
In UK, you do not need a degree to fly for an airline - yet. You do in the US, and it's probably only a matter of time before it becomes compulsory here. Do a degree - in a subject that both genuinely interests you and can be the foundation for an alternative career.