In a lot of pain please help?

so i woke up yesterday and my Achilles tendon hurt. so i tried to stay off of it and then i had to go to work and i was on my feet the whole time. when i got home it hurt a lot more and seemed a little bigger then my other one but not much do i wrapped it up and when to bed. when i woke up today it didn't hurt as much when it wasn't moving but as soon as i started to walk it felt like someone was sticking a needle through it. so i sat down and iced it. it hasn't appeared swollen at all since then but it is still very painful and sore it hurts if someone touches it and stuff. what could i have done to it? Help.... i know i need to see a doctor but had no car today and had to work yesterday