How to tell my family I have extreme social anxiety

I’ve been struggling with social anxiety for about the past year and every day it’s just getting worse and worse. It started out as being able to go to a social event, job interview, or party with just a little bit of nerves and sweaty palms, but as the months have gone by, I can’t even get out of the house without being scared. I can’t drive, go shopping, get a job, or even just have a friend over without freaking out, shaking, feeling hot, and crying. There have been times where I’ve gone into a panic attack with hyperventilation and hysterical crying just because of my nerves of socializing. I haven’t spoke to a single person besides my partner and family in the past 3 months because of this fear I have and I’m struggling so hard on how to talk to both my partner and family about this. My partner knows about it, but doesn’t understand how it actually feels. He thinks I can just “buck up” and throw myself into a social situation and everything will be okay. I know for a fact that that wouldn’t happen anytime soon because I’m not ready for it. But no matter how bad I want to get out of this black hole I’m in, it feels like I’m stuck and not even he can understand how difficult it is, despite me trying my best to explain it to him. Even a baby step in his eyes is a giant leap in mine. I haven’t told my family yet and I fear doing so because of the reaction they will have; that this is just an excuse not to get a job, that I’m being too sensitive, that I’m childish because I can’t do anything on my own, etc. To everyone besides me, this social anxiety is just made up in my head and I can get over it whenever I want…but trust me, no one wants me to get over this more than myself and I’ve tried. I want to get therapy but can’t afford it, and don’t even know how to talk to my family about this issue that I have, let alone talk to them about getting therapy. Social anxiety eats me up every single day, and I have yet to find a solution. I wish that other people could just understand how stressful, depressing, and intense this feeling is. I want so badly to get help and have people that support me and understand what I’m going through, I just don’t know where to go or what to do anymore.