Hi whitepigeon
My first instinct is to say: go and speak to the module leader for the subject you failed. It's pretty difficult for anyone here to answer your question. You need to speak directly to your institution to gain an understanding of why you failed and what you can do. Having taught at university, there is nothing more frustrating than students who have issues, but don't come to speak to you in time for anything to be done. It's your responsibility to sort this out and posting here won't help. You need to speak to both the module leader and perhaps the course director to find out what/if anything can be done.
Good luck. I hope you can get this sorted.