The best advice I can think to give is, 'don't believe the hype'. The media loves to play up conflict so only skim off the worst of society and attempt and scare us half to death to keep us buying their newspaper or watching their news reports. The very much have their own agenda.
I used to drive an awful lot and covered a wide area of the country in my job, but never saw anything which reflected the apparent anarchy which was happily exposed by the press. In fact I can't recall witnessing anything of significance. Don't assume we brits are quite as sedate and polite as our legend may have it either. Heh.
Another important aspect worth mentioning is, that it takes a certain type to become involved in any kind of conflict. Just as a pub brawl usually begins with an exchange of comments and dirty looks, as people size up to each other, so any incident on the road follows a similar interaction, with neither party wanting to back down prior to anything kicking off. Obviously there are exceptions, and 'what-ifs?', but so there are with everything in life.
I honestly don't think you have any real concern, it's just one's natural fear of the unknown. A good instructor will allay you of your worst fears too.
I actually think your age is an advantage too. I think I was into my thirties before I learnt to drive. Ultimately the feeling of independence one gets from being mobile is wonderful, it really is, and I strongly urge you to battle those fears and do it. I wish you the very best and please let us know how you get on or need more encouragement.