No, you're not a bad mom. I think it's important to understand that youre not tired of your toddler, but are tired of maybe the exhausting demands of motherhood. Or perhaps the uncertainty and fear of having an innocent soul totally dependent on you is weighing you down. It may help to know that many mom's go through this; it is normal; and it will get better.
Perhaps one or more of the following can help:
Take a break from caring for your little one if someone can babysit for a while
Reward or encourage yourself for the things you get right as a mom. It will boost your confidence
Shrug the "responsibility" aspect of it and just play or bond with your child
When you're relaxed, write down why motherhood is important to you and read that when you feel overwhelmed
Take some time each day to do things for you outside of being a mom. You need to feel that you still have a life.