I have a fair amount of writer friends who are immersed in the query trenches this summer. It is an exciting, anxious, and scary time for them. I know, I have been there before. They find themselves checking their email a gazillion times a day . . . at home, at work, on their phones. Every response is hyper-analyzed, Hell, even the silence is analyzed; and, in the the end, they are right back where they started . . . waiting.
My advise. Stop waiting and start living. For some that means starting another WIP. For others it means turning the computer off completely, taking the kids to the beach, or going out with friends For me, it meant checking my email only twice a day -- at lunch and before I went to bed. I started another WIP, double-dug and re-planted the garden, and caught on some long over-due reading. The offers of rep. came when they were ready, and me sitting glued to my email had nothing to do with it.
So there it is. Go forth and live. Bask in the accomplishment that you actually wrote an entire manuscript, had the fortitude to devise a query letter, and the courage to hit the send button in the first place. Then go rediscover the world around you.