Feeling vs dwelling

Hi there: I’m having trouble recognizing when I’m allowing an emotion and when I’m dwelling in an emotion. I’ve been practicing allowing emotions and I’ve experienced that magical *release* where I get through to the other side of an emotion/feeling.

But lately some deeper rooted emotions have been coming up I guess and I find that I haven’t been able to get to the other side of them. They hang around for most of the day. And then I’m reacting to people around me from this negative-feeling space and I just:
1) How do I not bypass the emotion but not dwell in it either?
And 2) How do I know when I can choose a more positive thought to get me out of the negative spiral?