How do i overcome social anxiety?

When In person I get so tensed and awkward when someone speaks to me, I cannot for the life of me hold a conversation, I have no idea what to say or talk about

When I’m being served in shops I always try and rush to get away quickly so I don’t have to stand and talk, and I know I come across so rude and stuck up which makes me feel even worse and paranoid but it’s literally anxiety!

On text/ replying to a comment on Facebook, I find myself rewriting a message atleast 10 different times because I overthink what I’m saying, or i take hours to reply because I don’t know how to respond, constantly worry with how I come across and I’m so sick of it.

I’m not very socially anyway never have been but it’s only getting worse, especially since becoming a mum and being with my only my baby and staying at home most of the time.

It’s even getting to the point where I can’t even hold a conversation with my own MOTHER!

Someone please help with some advice 😓x