My computer won't work when I write.

If I send anyone a E-mail I cannot get the mouse to go below the subjet line, The mouse pointer works on when I put in someone's name & when I go to the subject line but I lose the pointer below that & I can't write anything unless I write on the subject line. When I go below the subject line I lose the mouse & I get a capitol I & then the hour glass starts blinking like it's trying waiting to load but it is not loading anything. I can type here with the capitol I but I don't see the pointer arrow, I don't know why it lets me type here but not a E-mail. Can anyone HELP..
I will be gone until after 8:00 am but you can E-Mail me at jethacker1@csciowa,com . I could use any help.
Thank You
Jerry Thacker
Roseman2