By Rachel Smith & Paul Greaves A visit to the seaside turned into a nightmare for a mum and daughter who were left disgusted by what they found in their hotel room. Julie Potter and her daughter Katie, 16, have vowed never to return to the golden sands ofBlackpool after checking into their accommodation and finding mouldy walls and blood in the bed. They ended up roaming the streets looking for a place to stay after leaving. They said that there disastrous visit to Blackpool would be their last. Katie, who has been diagnosed with autism, asked for a night away in her favourite location, during…