Is it normal my social anxiety around people gets worse the longer i know them

For most people they become more comfortable around a certain group of people the longer they know them, like at work. But for me it's the opposite, the longer I know them the harder it is to talk to them. Every time I start a new course or job, it's like a fresh opportunity to make an impression and to really mix with people. I feel like I'll be able to do it this time and I'm really motivated to speak up despite the petrifying fear. But as time goes by, I make no progress despite all the effort and end up becoming disheartened and become less motivated and quieter and quieter. After a few months I just revert to assuming the same old reputation again as the mute person in the group. And then once I have that reputation, it just becomes much more difficult to talk up. It'd be much more noticeable for me to talk when I'm known as being extremely quiet, and so it's just much more scary. After 6 months I just want to leave, and try again in a new course/job with a fresh reputation.