It's okay to think of where you were last year. If anything just make a mental image of where you want to be. Just remember that you will get there and it isn't going to happen overnight. Go ride a shorter distance and work your way back up like the first time you started to ride. Unlike the first time, you will "improve" much faster. Each week lengthen your ride and or your speed.

Try not to think in terms of dread but rather think in terms of I'm getting closer to where I used to be. And enjoy your ride instead of I have to work out to get there.

keep a positive outlook to your ride