Whether or not new grads should have some med-surg experience before starting in psych is a controversial issue (and has been for a long time). Here is an old (but ongoing) thread on this topic you may want to look at, if you haven't already:
http://allnurses.com/forums/f46/why-...ng-250677.html
And I believe there are some others you could find, if you search for them or just "cruise" the psych nursing forum.
You mentioned you're "now not so sure" about psych -- what is changing your mind?