It's okay to feel bad. Especially if you make a big deal about feeling good, about wanting to feel good, about working on feeling good - feeling bad is a guidance thing too. Crappy to experience, but really, really useful. INDISPENSABLE!
Feeling negative emotion is an indicator that your alignment with your desires, with your INNER BEING, is slightly (or a lot) out of whack. This means that the negative emotion is here for you to be able to respond to a misalignment of your thoughts, and shift them in a more positive way.
You can't have one without the other, but you can have plenty of one and tiny portions of the other.
Get good at recognizing what your emotional guidance is trying to tell you and you'll get good, real fast, at pivoting away from the negative and moving into the positive.
Life will never stop providing opportunities for growth, for change, and with every single situation you encounter in life you will get the opportunity to either entertain positive or negative thoughts. That means an endless supply of choices between feeling good and feeling bad.
As long as you understand emotions for what they are (GUIDANCE), nothing can really knock you off your course. Feeling good is your natural state, but feeling bad is a warning.
Heed that warning and gently begin to shift your thoughts.
Every day can be a victory if you listen to what your emotions are trying to tell you.