Hey,
I have struggled with something fairly similar in the past with a relationship. After sending a text, I have found myself feeling very nervous or irritable only until I have received a message back from said person. If i didnt get an answer back after a little while, I would message again because I would worry. Something that worked for me:
I was suggested to try and do my best to occupy myself with something other than thinking about or waiting for a message back. And when I would get the urge to send another message after an hour or however long...to simply just not send another message and to wait. I know how much easier it sounds to be said than actually done. Not sure if this helps out much but I just thought I would respond since it sounded like I could possible relate.
-Mark