I sometimes go through something similar, checking and re-checking emails, facebook, forum, etc. It happens when i am overwhelmed and can't think of where to start doing something useful. What helps me is to give myself a time i will check all these things--such as morning and evening--check each thing once and turn the computer off. Or if you are using your phone, put it away unless it rings or you get a txt.
Turning stuff off or putting a phone away where it is not easily accessible helps me to break the perseveration and train my mind on something else. It doesn't usually matter what the "something else" is--as long as it is not rechecking stuff online.
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"Them that don't know him don't like him,
and them that do sometimes don't know how to take him;
He ain't wrong, he's just different,
and his pride won't let him
do things to make you think he's right."
-Ed Bruce