I keep my text's so I can check back if needs be. I do delete down when the mood takes me. I didn't used too. I was obsessive over that been cleared as well. I am now a little easier on that. I do clear out text at the time as they come through that are one off texts such as from taxi firms who tell you, it's on it's way, it has arrived and it has now dropped you off. Other such I clear down are one pin sign in messages, companies reminding you your bill is due to be paid and so on. I have no need for them so they must go.
As for emails OMG yes I am the same. I have three email addresses. 1 is personal, the other is recovery/business and the other is my comping email.
I have all three set up on my mobile as it is easier to clear down from there. My comping email is cleared down two or three times a day. My junk box is erased once checked two or three times a day. My delete email is also deleted everyday so I can see where things are and it is neat and tidy.
My other two emails don't get as much in them as my comping email addy does so it doesn't need clearing down to the same extent as my comping email however they are checked a couple of times a day, dealt with, filed or/and deleted from the delete box as well.
Neat, clean, tidy and know where everything is is the only way I can work