Painful sex......vaginismus?

So I've been sexually active for the past year and Besides first time sex it's always Pain free. However, a few months ago I noticed that when my partner and I tried to have sex there was awful pain down there and it felt asthough he was 'hitting a wall' I assumed that maybe I was just try as after a few thrusts the pain would ease...last week we tried to have sex but the pain was unbearable I started crying and I got extremely scared that something is wrong with me:( I did some research and vaginismus (when the muscle in your vagina titen) seems to fit with my symptoms but I'm confused as it never used to be painful and I'm too scared to go to the doctors just yet....so I'm just wondering if anybody has experienced vaginismus and if it's likely that that's what I have?:(