Thank you esmi and kulwant2sin for your speedy replies. I tried all the suggestions you gave – the one that finally worked was reuploading everything from a fresh wp download. I’m so grateful that it’s all working now – thanks for your help.
Now it’s working properly again I thought it was time to do a bit of housekeeping, so I decided to update all my plugins/themes as I think this is where my problems began. I updated them one by one but the process was incredibly slow – could this be linked to the same issue?
Thanks again for your help.