Most of these wounds are self inflicted and you can start solving them one by one, mainly by stopping your bad habits.
Stop working 90 hrs a week for your employer. Don't let them exploit you. Don't give up your free time voluntarily.
Stop working for this company and start interviewing at other companies. Prioritize a place where you have a couple of colleauges that you can learn from, and socialize. You will learn from them, and you will also learn that they are not perfect, maybe you stop treating yourself so harshly.
You don't need to start with FAANG, just find a place where you can learn at a healthy 40 hrs (or less) rate. You can practice leet coding, but do not put to much pressure on yourself. Just solve two problems a day, in a year you will be probably ready for interviewing at FAANG companies.
If what you say is true and you can ship things, you are good at mobile and web, on call, etc, you can probably get a significant raise, too. Start looking for a new job, and even if you feel down, try to fake that you feel confident.
Stop accepting on call duty without compensation.
Stop thinking you are just simply "bad at networking". It's a skill that can be improved if you actually want to improve it. Start even if you think you are "lame", go to meetups, apply to jobs, start a running club, or anything, just take small steps and start improving your networking skills as soon as possible.
Stop panicking that you are already 28 and don't have everything figured out. You are still young and can easily turn your life around.