I know what you mean, I get this feeling off too both caused by a certain situation or randomly and it feels like it'll never pass but I can promise you, it does pass.
What helps me is firstly try and fix anything I can with the problem that fixed it if possible, then I do some gentle exercises such as going for a walk while listening to music, dance around my flat, tidy up etc, go for a bath, when my back and chest are tight I ask my bf for a massage, I watch my favourite funny TV show and I also make sure I talk about how I am feeling and also the situation that caused it if I feel maybe someone else can come up with a way to help me with it. I also try and get as much sleep as I can. Think can be hard as I have an insomnia at the best of times, let alone when I feel like crap.
All these things can help but it wont get rid of the emotion entirely but over time, be it a few minutes, hours or days, it does help to lessen what I am feeling. Accepting what you are feeling and time are the only sure fire ways to get rid of the unpleasant feelings, mentally and physically.