No UCAS reference and a weak application, what do I do?

Im not a mature student, im 17. I'm not in school right now. I've only had one teacher recently and she didn't know me very well, plus that was 6 months ago and there's a chance she won't remember me at all. I have never been employed by someone outside of my family. I saw someone say if you talk to your universities they might accept you anyway if you have a strong application, but I don't. I only have a level 2 qualification, English and Maths GCSES, and an upcoming level 3 qualification in an irrelevant subject. I doubt a personal statement no matter how great it is could make up for everything I'm lacking, and i doubt mine is that good. If anyone has any advice it would be greatly appreciated, I'm doing this application alone.

I have checked their requirements and I do qualify, I just worry I won't be as strong a candidate as the others since I'm applying for a business course and the level 3 qualification isn't a business one.

I was about to email my teacher, but I'm not sure she's in a position to give me a predicted grade. I don't know what makes someone eligible for that.

Sure. Just because one candidate might be stronger or weaker than another doesn't mean that only the strong candidates get places. Many universities simply don't get enough candidates for their courses, and have to lower their requirements and offer them through Clearing on results day. So as long as you meet the requirements, and aren't only applying to very competitive unis, then you'll likely be fine.

Also, it's not a matter of someone being "eligible" to predict your grade, it's simply whether she feels that she has sufficient knowledge of your academic ability to be able to make a reasonable prediction. She might not be comfortable to do so. Hence why you need to ask.