From personal experience the first thing i recommend is trying to remove some layers of stress. So if you have a really full mental inbox and have lots of things on your mind. try to remove all unimportant things from that list.You need to remove some of the pressures of daily life to give your self some space to think. It might do you good to just go out for a walk and just allow your brain to unwind a little. Just get a tiny bit of space or respite, just to allow you a bit of a mental break.
Put some music on while you do it, to stop your thoughts racing. you need a rest and you need to come down from level 10 stress to a more managable 7,6,5 etc. Even if you just do this one thing every day, get up, get out for a walk with your music on or favroute audio book, it will help to form a small period of time where you're not thinking too much.
If you talk to people who care about you and love you, you will find that that everyone just wants you to be ok. They probably worry about you more than you know. Don't supress how you feel, talk about it, take it's power away. I used to feel like you, i used to over think interactions because in some way i guess i wanted to be part of the crowd, I had no confidence, it felt like a real effort to think of anything to say of relevance. I always felt like i was on the outside, and i had some pretty low times in my twenties.
Now im 44 and i have acheived so much in life that i never though remotely possible at the time. I am probably the most extroverted person I know now, my whole mood has changed massively for the better. It's hard to see down the road when your in the moment, but I promise you, you keep fighting and don't let it beat you. It will fade eventually.
If you arent taking an anti depressant such as sertraline, ask your doctor about it, its very good for anxiety and might just give you a little break till you get back on your feet.
Me and my partner have gone through periods where i was the bread winner, then her, then back to me, now we both own our own business and we face the world as a team, its not my money or hers, its ours. Tell your partner how much he means to you, and good luck with your journey, don't give up, this isn't going to beat you. You sound like a really nice person and you deserve good things in life.
Keep fighting, and you come back here when you are struggling and we will be here to support you.