Balance deliberately thinking to feel positive emotions vs. feeling negative emotions

Good morning! I recently joined scholars (and am thrilled about it) – and already have a question.
If I know I can deliberately think the thoughts that create positive emotions but I also know I need to allow negative emotions and let myself feel them, how do I know where the balance is? Why isn’t my ultimate goal to only create positive emotions and get rid of the thoughts creating the negative ones? (which I am pretty sure it isn’t so I’d like to have your thoughts on this :))

Thank you so much! Looking forward to taking this journey with you!