I was in exactly the same position as the OP at the beginning of this year. I've been flying turboprops and then an RJ since 2008. I've been an FO for all of that time. I've interviewed twice for one of my dream jobs over the last couple of years and have fallen at the last hurdle both times. I was feeling rather sorry for myself, very lackluster and stale, and just felt that I wasn't making a difference in the world.
In April I decided a change was in order and I took a months leave unpaid. After three weeks I found I was really missing flying. I went back in mid May and put a fleet change request in. I've just finished my conversion course for my new type and have fallen in love with flying all over again. If you have the option to switch fleets, I'd say go for it!
But more than anything else I would say that my month off gave me time to really reflect on what is important to me. Flying is all I had ever wanted to do, and I was distraught that I was bored. Then I realised, I'd built it up so much that it was consuming my life. Family are the centre of my world now, flying is just my job, an extremely enjoyable job, but no longer something I pin all my hopes and desires on. I'm very content now, all that was really required was a change in perspective.
I've recently volunteered to give talks at schools and universities and already I am finding it very rewarding to encourage a new generation of pilots.
Good luck with whatever you decide to do. I think most airline pilots reach this point at some time in their careers.