Help! i am being bullied at work and now i have got a disciplinary against me!?

i am a painter and decorator have worked with the same company for 3 years and all has been ok until 3 months ago someone drove into the back of my works van. i informed my boss straight away. the next day i went to the doctors and was told i had whiplash injuries. the next thing my employer rang me to pick up the van saying that i was not insured for it! i was very shocked as i had been driving the van for 3 years totally oblivious of the fact i was not insured. i have got a drink driving conviction from 6 years ago and the company did not pay the excess amount on my behalf! i was very upset about this and shocked! i told them i was seeing a solicitor about the matter and was bombarded with a string of verbal abuse! since then i have been taken into the office dozens of times and i have had all the managers giving me verbal abuse. i have been told that i am too slow at my job and this week mon/tues i was told that i was to put someone else's work right as we work as a team and the bloke who did the work incorrect is on holiday, and this snagging is in my own time and i wont be paid for it. Me and my partner are newly approved foster carers waiting for a placement to arrive we have been through the strictest checks and we are proud to be ready to take children into our safe care. On thursday 25/3/2010 i was called yet again into the office what i was told has sickened me to the core, they said that an allegation has been made against me about an alleged ault on another member of staff, i did not have a clue what they were talking about but when they told me it was 6 months ago and me and one of the lads had what can only be described as a play fight accrued, the lad grabbed me and i him and we fell to the floor laughing, as were all the others who were witness to it , i clearly am being set up by my bosses and the lads who are "cashed in" with them. i feel sick and trapped, i have also got a witness but i am afraid that he wont stick up for me as he fears for his job too! when i went in the office the manager was trying to blackmail me into making a statement saying they will give me a reference for a new job i applied for if i make a statement what are my rights? i don't want to walk out as i have not done anything wrong i feel trapped and my partner is in bits!! please please help us!