Sorry to hear this. You definitely have the ability to pass - you're a graduate!
As someone who failed first year exams twice and then was permitted to repeat the year, I can understand what you're going through.
One of the main things I've learnt through failing and resitting exams is to study the same thing more than just a couple of times. I realised to learn/commit to memory I need to have been exposed to it at least 3-4 times. First time attending the lecture, second time reviewing and learning it then repeating a couple of times. And I return to the same material, I spend progressively less time covering it. So 1hr, 30 mins, 20 mins etc.
Another thing I learnt is to work smart. I can't emphasise that enough. There's SOO much content in medicine and to try and learn every single detail is almost impossible. I would try to focus my revision using learning objectives provided so I wouldn't waste time learning intricate biochemistry if I didn't need to know it for the exam.
Also, I learnt that I need to work consistently throughout the year in order to pass. A lot of medics tend to leave revision to the last minute (and it can work) but this definitely doesn't work for me as I just panic and the anxiety takes over, leaving me very unfocused. So I worked in the evenings every day after lectures from the beginning of the year.
Failing exams can also have a massive effect on your confidence. In my case, I lost my confidence massively after failing even my summer resits but you've got to tell yourself you definitely have the ability to pass, otherwise the medical school wouldn't admit you in the first place! Tackling exams is about having the right mindset and being confident in yourself - once you've done all you can in terms of study, believing in yourself that you WILL pass.
Talking to other people who had failed in previous years is also really helpful I think - it puts things into perspective and shows that passing third time around can be done!
Another technique people find useful is summarising the very key points from a lecture onto a single side of A4, which means you cover the essentials and it saves time nearer exams.
All the best, hope everything works out!