1. Find someone with whom you can share your goal/passion. It does not have to be a business partner right away. You will find a lot of communities on the web for people working on your project, for small start-up businesses, etc. Maybe it will give you some motivation.
2. Accept that there are tons of similar products globally, and some will be successful and some will not. Besides, even if a product on the market is similar to yours, it doesn't mean that you can't beat it.
3. Remember that the process of creating a product, introducing it to the market, and further development is complex and often takes a long time to get the results you want. Don't give up in the early stages!
4. Learn. Observe how creating products and introducing them to the market looks like for others. See what they fail to do and learn what they are doing right. It is also worth establishing closer contact with such people. You can get valuable advice from them (you may even find that some of them have had similar problems to yours).