Can I become a psychiatrist?

You need a medicine degree to become a Psychiatrist.

If you really want to become a Psychiatrist, do a related undergraduate degree, psychology, neuroscience, or biomed (I don't know how likely you'll get on a degree like biomed though because of your A-levels), and then do medicine at post-graduate level.

So there's no chance for me to do an undergraduate degree

No, I'm afraid. If you really want to become a Psychiatrist, I think it's a good idea to do a Psychology degree, and then a med degree, and then you can specialise in Psychiatry. Because doing a Psych degree gives you a real insight into whether Psychiatry will suit you, I've read a lot of Psychiatry journals during my course.

People often don't seem to realise though, that Psychiatry is a medical speciality, just like a medic would specialise in general practice, paediatrics etc, they can specialise in Psychiatry.

Can I ask why is it you want to do Psychiatry, as opposed to the likes of Clinical Psychology?

Clinical Psychology doesn't require a medical degree. The main difference between Clinical Psychs, and Psychiatrists, is that Psychiatrists can prescribe medicine, so can offer medical treatments to patients.

Clinical Psychology is insanely competitive though.
A lot of Psych undergrads enter their degree wanting to be a clinical Psych, but very few graduate wanting to be clinical Psychs. And even fewer actually end up being clinical Psychs.

I always had the passion to do medicine I loved science so much that I couldn't think of another career plan but sadly my science gcse was a D it was because my teachers messed up my ISA and for core science I got C and I needed an A to do science a levels. So then I read about phycology I read about psychaitry and it really interested me. If you could give an estimate how long would it be to in total as you said I would have to get a degree in phycology first and then med school how many years would it take? I'm willing to study extra years for this