I was diagnosed with dyslexia as a kid and was fortunate to be given extra support. Despite this, I struggled at school. I felt stupid because I couldn't keep up and I was a bit deaf as well because I had glue ear, so I had difficulty engaging with the class. I'd sit at the back drawing pictures.
However, Davena Hooson, who taught me in my final year at Trefonnen Primary School in Llandrindod Wells in Wales, recognised that I was creative rather than academic and she encouraged that. She made me feel special and that I had something to offer the class, even when I did terribly in my Sats.
She was full of magical stories and would tell us about growing up in Jamaica, sitting on the harbour with great white sharks under her feet. She put on plays and got me to act in them and write bits. My confidence went through the roof.
Once she brought in a bottle with a message in it, full of clues that we had to decipher. We then made plays out of the clues. It really fired up my imagination and kick-started my love of reading and writing. I'm so grateful to her for that.
She talked to us like we were human beings and I hadn't had that before - some of the teachers there were quite harsh. It felt as though it was a friendship, I just loved her. Maybe that's why I always used to call her "mum" by accident.
A year and a half after I'd started senior school, my family moved to Cardiff and I went to Llanishen High School, which was huge. The information about my dyslexia wasn't passed on and I never mentioned it because I didn't want to be singled out for being different. Now I realise that was silly because I might have got extra time in my exams, but back then I just wanted to fit in.
Mrs Smith - Nicola - taught drama at GCSE and A-level and she rescued me again. I was a smart kid but I was going off the rails. I wasn't turning up and as I got older I lost interest in school and focused on DJ'ing in nightclubs. I could easily have dropped out but she kept me there.
Like Davena, Nicola encouraged me enormously and pushed me in every facet of drama. She worked me hard because she wanted to bring out the best in me and I'm so grateful for that. We devised a few plays and with her encouragement I wrote a couple myself.
For GCSE we put on Who's Afraid of Virginia Woolf? by Edward Albee. I played George, which was Richard Burton's role in the film. It's a mad part for a kid but it was an amazing experience and I relished the challenge of being pushed. I think I got the best marks in the country for it so I was really pleased.
I haven't seen Nicola since the day I left. I know she's not there any more because a girl I used to snog at school is the drama teacher now.
However, I did get back in touch with Davena through Facebook. She was very kind and told me how proud she was of me; it meant a lot.
If it wasn't for these teachers I don't know what I'd be doing now but I certainly wouldn't be an actor. They gave me faith in myself.
Tom Cullen was talking to Kate Bohdanowicz. He is supporting Cancer Research UK, the official charity for the 2015 Virgin Money London Marathon. To support the charity's biggest ever marathon team and help raise pound;2.5 million, visit www.cancerresearchuk.orgmarathon
Born 17 July, 1985, Aberystwyth, Wales
Education Trefonnen Primary School and Llandrindod High School, both in Llandrindod Wells; Llanishen High School, Cardiff; Central School of Speech and Drama, London; Royal Welsh College of Music and Drama, Cardiff
Career Actor and writer, best known for playing Anthony Foyle, Lord Gillingham in Downton Abbey