I know how to merge topics less than a full page long, but I'm not sure about longer topics. If I were to do it, there's a risk of unintended consequences, including mixing up journals out of order, and even the possible loss of your journal, which would be a shame.
It may be that one of the other moderators can do it. But if not, a good way to deal with it might be to edit the first post in your second journal to include a link to the old journal. For example, you could edit it to say "Welcome to the continuation of my journal! For older issues from 2005 and 2007, click on this link: <link>".
BTW, RedRox is still a member here, just not a moderator.