Yeah chavs sadly are very present at Thorpe, you will probably find Alton much better as overall the crowds (bar travellers day) are usually much less of a pain.
With your fear I think the best thing is to do is to just not think about it and just hop in the queue line, don't compare any other coasters to the ride in question, just hop in the queue and give it a go.
When I went to Portaventura this year I had a huge fear of Hurakan Condor, this fear mainly came from me comparing Detonator to Hurakan Condor,
Detonator left me shaken after every ride so how could I possibly do something 3 times the size? It turned out Hurakan Condor wasn't as intense as Detonator anyway.
I shouted and screamed all the way up the tower and I trembled like a leaf but it came one of my favorites in the park,
I think fear on rides is more of us building the ride up to be something terrifying, most of the time we get off realizing how stupid we were for being so afraid!
Maybe you'll overcome this fear this year or in 5 years, do it at your own pace.
With Alton I have to say maybe try Nemesis (sure its intense but its smooth and a great ride) to get used to inverting.
The Smiler is probably another good option but obviously inverting 14 times in a few minutes might be a little overwhelming.