Ok, with my HR hat on, the advice that cherrypie has given you is spot on. Act now rather than delay and your manager needs to help you.
Answer really depends on what response you get when you raise it. Perhaps do it as a business case sort of model to try and keep it from feeling too personal and that you are 'failing' - it could be all sorts of things that are nothing to do with you, e.g. job design
Maximus is also spot on - if you are a valuable commodity, future employers aren't going to be phased by a job on your cv that turned out to be a turkey - the trend these days is for much shorter periods with one employer than it used to be (the old 'job for life' concept is well and truly dead in most cases).
In terms of purely practical resources have a look at a book called Getting Things Done by David Allen - you might find it helpful and it is quite cheap. He has a website and there are loads of resources about his simple system on the internet. A lot of different types of people I've recommended it to have found it useful - some in terms of being able to evidence their overwork!
Please don't get yourself to the stage where you get ill over this.
Oh yes and one final thing... as a fellow perfectionist - you have to be happy with turning in work that's 'good enough' in times of extreme workload else you will go bonkers! Have you got a friend or ex-colleague that you could ask to help you identify what's 'good enough' in your context?
Wishing you all the very best
