One term, 4 letter word!!!
Is where it is at, not the complex teaching that is in many arts.
Some say size does not matter, well it does and most arts that came out of the east, were for much smaller men, than todays very strong and bigger men.
Aikido is one that was designed to deal with it, even so it is still lacking.
Using the fight or flight response that is built into humans, was always and still is (if not trained) there. But proper training, should have that in it.
Firearm training, knife training, stick training, all evolved to take care of size. Now they have chemicals to off set attackers.
MA is good training, for many reasons, disipline, exercise, fitness, following instructions. The art of self defense, is not, fighting! Good solution, not being there, avoid, escape
Compitition is good, boxing is all about that, in the ring, not outside of it.
Attitude must be first and foremost, as in flying a plane.
Start by working out in a gym, running. Good health is best, fighting is not about good health
Many on these forums, you say, lets meet and train, consider that an attack of some kind, LOL
They have just shown you, their attitude.
I like your post, just rambling some...