I’ve suffered with bulimia for 9 years. It’s had a huge effect on my teeth and knocked my confidence massively

Bulimia as you know cause acid erosion, removal of protective layer of your teeth (enamel), causing sensitivity, loss of bite and eventually causing loss of teeth, and malocclusion!You need to make an appointment with a knowledgeable dentist to have a complete evaluation first so the function and your bite can be evaluated besides cosmetic dentistry! The restoration of badly eroded teeth may require porcelain crown, but the function of your teeth must be considered prior to having crowns done! the number of how many crowns is needed or the cost, depends on the extent of erosion as the result of bulimic condition.

Thank you so much for your question. 
I am happy that you are now on your way to a beautiful and healthy future. 
Although you are now suffering due to the extent of devastation you have encountered in the past, please be assured that today we have a lot of options that are life changing. You need to look at this option as an investment into your future. Cosmetic dentistry is not cheap, however it is worth every penny, due to the amazing results and longevity. 
Good luck to you!