I know it's boring and people say it all the time, but if you feel you have been wrongfully arrested you could consider suing the police. For as start there is the financial incentive, but long-term it is one of the ways in which you can help prevent other people from being treated in the same way that you have yourself.

An easy place to start is Irwin Mitchell (hopefully spelt right) which is a national-scale solicitors firm with expertise in suing the police (amongst other things).

Sadly, before you can sue the police you need to wait until the criminal proceedings against you have been completed. It may be worth contacting a solicitor sooner rather than later though as they can advise you as to what could potentially be of importance later.

In the past there have been a number of groups offering advice on legal matters to activists. I don't know which ones are currently active and which ones not thuogh. Perhaps someone else does.

p.s. even if the details are a bit sketchy, it sounds like a great action.

It can be found at  https://www.indymedia.org.uk/en/2007/09/380280.html