Consistency and persistence is the key here.
Many people, or let's just say I think it's going to be common that we start this therapy with good intentions, but it can still be a struggle to regularly do the therapy daily because of how busy our day is. So maybe we do therapy one day, miss one day, do it again, miss two days... I know it's tough, very tough to find time and to stick to the therapy daily. This is not exactly a fun habit to get people to do. It feels like work at first, for sure.
There is no way around this "work" every day, if you really want to see the differences start to add up in the way you think. If you are doing the therapy, first and foremost, that is great. It might not feel like it now, but you are doing something for yourself that will have lasting effects. Stick with it. Keep doing it. This is something you know you need, and it's tough to change years and years of habits.
I'm glad to hear you are in a job. I understand that's stressful. Most of us avoid too much stress, but when we allow ourselves to start avoiding, that is not the better path to be on.
A day like yours does sound very stressful for a socially anxious person. Don't get down on yourself for not feeling able to apply all the therapy to every anxiety moment in your life now. Spoiler alert: that's not how therapy is going to end up anyway. You won't be anxiety-free of everything in your life in all situations just because of this therapy. Anxiety is a natural emotion. You will just be more rational.
If I can suggest - try to do the therapy in the morning. I know, you have a busy day. It's hard to make extra time in the morning. I know, I know... but, you speak of being so tired and defeated by the end of your work day, and then you go home to do the therapy. With all that feeling from the day, and being tired, I'd like you to compare the feeling of doing therapy in the morning and see how you feel throughout the day when you do it in the morning vs in the evening. First, it's great you're even doing the therapy. If you can only manage the evenings, that's still good. Keep with it. If you can try to wake up 30 minutes earlier, go to be 30 minutes earlier... do the therapy in the morning, maybe when you are feeling calmer, while you still have energy. I found that when I did the therapy in the morning, the calmer feeling seemed to help throughout the day. When I did it at night, it was still beneficial, but I didn't have the same benefits, not quite as much, during the day. Somehow the message stayed with me during the day if I did the therapy in the morning. But also for me, morning is a better time to focus and work on projects. By the evening I'm less mentally focused. Perhaps you have a different style of working, perhaps you work better at night. But, if you can, just try this. See if you can try one week of doing the therapy every day in the morning and see if this makes a difference for you. I'd be interested to hear your comments after that.
You're on the right path for yourself, so stay on it. During the early going, it won't feel good. The ANTs will look for any and every way to throw you off this track. You'll have some setbacks too, naturally. Stay on the path, though. You are doing the right thing.