Does anyone have advice for severe texting anxiety?

I texted someone i haven’t heard from in awhile (who was my supervisor) to ask how he was doing because I want him to know if he was doing alright. But I also texted saying I would be around to take shifts soon, and now I’m worried he thought I was only asking how he was doing to get shifts— not because I actually care (I DO care about him!!) and I want him to know I genuinely care, not just want to get shifts. What should I do?? I feel awful. I keep telling myself he probably does know I was sincere, but i have brittle anxiety and it’s hard to tell myself this. He replied saying thanks and that it was nice to hear from me, BEFORE I told him i was around for shifts. But when I then told him that I was hoping to get shifts soon he didn’t reply. Can anyone reassure me or give me advice? I’m really beating myself up.