Hi Rob,
First of all, well done on overcoming your fear of flight
The main problem with turbulence is that it is invisible and hard to predict. We will never fly through big storm clouds - which we obviously can see - and in which there certainly will be turbulence, but otherwise we make educated guesses using other aircraft reports and various known areas and phenomenon such as jet streams, and storm clouds.
Driving along a cobbled road, or an off road track describes most light and moderate turbulence pretty well. Another way of thinking about it is like being in a small boat on choppy water - you get thrown around a bit but are essentially OK.
As has also been stated, modern aircraft are actually very strong, and even if they are being thrown around, they will hold together. They certainly won't "fall out of the sky". Some turbulence might occasionally cause a momentary reduction of lift, and passengers and crew have been known to hit the cabin ceiling, so it is always a very good idea to keep your seat belt on - we always do in the front.
When in turbulence as a passenger you might find it better to close your eyes. The human brain gets confused when the ear's balance organs are reporting turbulence and movement but the eyes cannot see the movement because all they can see is you sat in the cabin which does not appear to them to be moving. This confusion can lead to nausea.
So don't worry. Turbulence is a nuisance and can be quite uncomfortable - but that's about all - and we will do our very best to avoid it.