Well applying and seeing what happens is probably the best idea then. I think you really ought to get some work experience though... Do you think you could get a summer job? Do you know anyone who might be able to help you get a job (it's cheeky but it's often the best way to get your first job). If you don't have many jobs going at home perhaps you could live in your accommodation over the summer? When does your lease begin?
I think that the dissertation is more about time and effort than intelligence. I'm not trying to slag off your efforts so far but maybe it's the extent of the work you have to do that is intimidating. All I can say to this is yes, it's intimidating, but your degree depends on it and so do your job prospects after uni.
Back to the job prospects, I don't think you can have a realistic idea without having work experience. It just puts things in perspective, especially if your job isn't enjoyable- it can be motivating for your academic work. Plus, you'll be earning, and that is great for fulfilment and confidence if you can get and keep a job (and I'm sure you can). Having your own money is another source of confidence and happiness, just because it's so nice to know that this is YOUR money you're spending, you know?
The one thing I would say with regards to your academia though is that you're on TSR, which means you're probably quite hard-working / intelligent anyway, and so you can probably succeed in your dissertation but maybe you're lacking a bit of confidence. I'm only in my first year so I can't really understand what it's like, but it also depends on your subject as well.
Speak to your personal tutor about your situation academically and they have to help you cos its their job.
So yeah, I'd say get a job over summer if you can, whatever that job may be. And speak to your personal tutor. And maybe talk to your mum about the situation? If your dad would get a bit angry... But if you work over the summer and end up getting this job, maybe you can pay him back when you start earning?
I'm sorry, I'm sure you've thought of all this already. You know what you need to do, the hard part is actually doing it. Good luck.