Yes you can declare yourself bankrupt but it will cost you £700 unless you are on certain benefits in which case there could be a reduction.
How much are your debts and do you have any assets which could be at risk if you do declare BR?
I suggest that you speak to an expert as to all the options open to you. Click on the expert link on the left hand side of the page and give one or two a ring for some free advice.
The friend in my adversity I shall always cherish most. I can better trust those who helped to relieve the gloom of my dark hours than those who are so ready to enjoy with me the sunshine of my prosperity. – Ulysses S. Grant
You can declare bankruptcy if you are insolvent and it's the best option for you. We don't know your situation, so please post a few more details, or speak to an expert for advice.