If you regret getting a cat the very next day, it's probably because raising a cat isn't as simple as you imagined; it requires a lot of time and energy.
First, you need to provide your cat with proper food, shelter, and healthcare, which requires a certain amount of money and time. Second, you need to provide your cat with appropriate training and socialization to help them adapt to family life and become family members. This requires even more time and effort.

If you've decided to get a cat but aren't ready to take on the responsibilities, it's best to find someone who can better care for them. Also, if you find yourself feeling guilty or anxious about owning a cat, try seeking professional help and advice to help you manage these issues better.
Finally, remember that owning a pet is a long-term commitment that requires a significant investment of time and energy. Before deciding to get a pet, make sure you fully understand and are prepared to take on these responsibilities.