A strong body is a good asset. A strong mind is a very good asset.
If you are not comortable to deal with an opponent 50 lbs heavier than you, there is something wrong with your Jiu Jitsu.
Be positive and the challenge will be easier.
The most important thing is not victory, the most important thing is don't get defeated.
Study is a life long pursuit.
In life, when presented with any situation, breathe, take your time, focus and then decide what to do.