http://www.acas.org.uk/
without knowing the full details of your employment it's hard to give a definitive answer, but you should phone ACAS who can give you the best advice on your options
you can also speak to your local citizens advice buro who can also give advice
you should also make an appointment to claim job seekers allowance immediately, and explain the circumstances to them.
your boss should confirm your termination in writing and give the reasons for termination. i suggest you don't make any further contact with your employer until you have spoken to ACAS and/or CAB for specific advice regarding your case. you should give them a call in the mornig, and call the job centre to make an appointment to see them. you should of course also make some appointments with job agencies to seek new employment elsewhere
due to the length of employment, size of company, and the informal nature of the termination, if they seek further advice they could find that they may be able to offer you as little as two weeks pay in lieu of notice of termination of employment and two weeks statutory redundancy pay (depending on what the terms and conditions of your employment say - ie. your contract). along with that you are due payment for whatever you have worked to date, and unpaid holiday entitlement. thus you may only be entitled to as little as four weeks pay for them to terminate your employment legally and "fairly". if you are paid monthly then it could be a months notice and redundancy pay. ACAS and CAB should be able to clarify this for you