Yes it is stressful. Especially as you have no control over the result - all you can do is cheer hard for your team.
I've been in this situation before with my local Australian Rules team... In 2013 leading in to the AFL Preliminary Final (the game to get into the Grand Final), much the same as the NFC Championship is to get into the Super Bowl - my team the Hawthorn Hawks had lost 13 straight against the Geelong Cats - they just had our measure, most games were close and Hawthorn would always find a way to lose it -- it was like a curse.
Down by 21 points at three quarter time - I had given up - the Hawks hadn't, they dug deep and finally buried the curse ... and then went on to win the next three AFL Grand Finals.
I am confident the Rams can do the same come Sunday.
GO RAMS !!!!!!!