I'm scared of the phone

Stacey 👑 • 1⃣9⃣🔮👓📱🇬🇧🎄🐸🌹🙋🏻👫
For as long as I can remember I've been scared to answer the phone, if I don't know the number I literally can't pick it up and I can't phone people either. I feel like my SO is fed up of it, if I ever need to phone the bank or anyone he'll offer to do it on my behalf but other times he'll say "why didn't you answer it" and I just say I couldn't and he's like "well you should have anyway@ yesterday I got a phone call that I didn't answer and they left a voicemail saying it was about a job I applied for and when I told him he asked if I answered it and I said "no I couldn't but even if I did I wouldn't be able to hear her because you were playing a game" and he just said "you should have just phone her" 
It's getting in the way of me getting a job :-( I was okay for a while but since my confidence has been kicked I'm too scared again.
Since I moved away one of my friends has tried phoning me but I can't bring myself to answer it and he has messaged me but only to play mind games, he got into my mum about it and she told him that I can't answer the phone but he doesn't get it either