Being a degree holder for the sake of holding a degree is pretty pointless, tbh. The whole reason to go to uni is to study a subject you really enjoy (then find out its a lot harder than you could have ever imagined...lol). Like myself, im interested in human disease, specifically related to neuroscience, so I did a Medical science degree. As if that pure torture wasnt enough im just about to finish a Masters degree, where ive been studying developmental disorders.
Im incredibly interested in the stuff ive been studying-so much so, I want to make a career out of it, do a PhD next etc.....The whole reason they ask for good grades at A-level is because you wont get good grades if you arent incredible interested in the topics you chose. Also, because its a sign you can possibly handle the pressures of university-which are intense, believe me. Just because uni "looks fun", what with all those nights out or whatever, doesn't mean you dont have to work incredibly hard, which I believe you can only do if its something you are so interested in, you want to make your living out of it-or try to anyway.
So no, I wouldn't recommend a degree. And as for your A-levels....sounds like you aren't enjoying them, so look at other options (maybe other subjects, or as you say, diplomas in something else) that you actually enjoy, and do that instead. Life may not be that short, but better to not waste two years in hell when you can be doing something you actually are passionate about