Is there any way for me to travel from the UK to China by boat or land/rail through Europe?

Basically I'd like to travel to China, but I have a fear of planes unfortunately. So I suppose either by boat or a month long journey through Europe would be the only way. I would prefer the boat way tbh. Any feedback on this would be helpful.

Yes... it's possible... in fact, there was a series on the BBC a few years ago when Nigel whats-his-name made that trip. It is a much longer trip than a month, however. The Orient Express is still running and that is usable for part of the trip.

The trans Siberia Express is still running, there are many tour companies that combine the Russian train with a Chinese train, and as such bringing you to China, but the return will almost always be by plane. So you would need to get it arranged to travel by rail both ways or find transport over water for one way.

This is a 6 to 10 day journey, if my memory serves me well.
That train leaves from Moscow, so add a few more days for the European leg of the Journey, trains to Moscow leave from Amsterdam (and I think also from Brussels and Paris.)

I have tried to find a cruise-line before, did not find any that did go direct, and the long way round will take months and a fortune.
You could ask in the Cruise part of Yahoo answers, as the people there are much better at home in sea travel.

By ship: P&O from Southampton (UK) to Hong Kong, from Hong Kong 3 hours train ride to Canton (Huangzou).
By train: W.Europe to Moskou, in Moskou by Transsiberian until Vladivostok or earlier stop where you can make connection to China. In both cases back by plane. Bon voyage.