I have had this pain right below sternum its very painful i can feel like a tight knot is it colon or hernia? i have tightness all way across too.

Probably not, but...: Your depicted scenario may not suggest concerning colon or hernia. But, it's a good idea to watch, collect, and record the detailed feature and degree of all symptoms with detailing the sequence of events, with special attention to if being position-physically related, and bring those to see doctor who usually can figure what you got after history, physicals, and tests as needed. Best...