It is important to understand that for any given civilian to need to use a fighting method is extremely rare. 'Self defence' can be achieve by avoiding situations where there are likely to be hostile people, by talking to the potential attacker and by running away.
If you are a civilian defending yourself somewhere with no CCTV footage this could get you in a lot of trouble.
So if you are going to learn to fight in a self defence context you need to be able to scale your technique to be an appropriate level of force to the situation at hand. This is not a strong point of the techniques taught in krav maga.
Krav Maga is a system designed to be part of the training of soldiers. In particular it is designed to be taught to Israeli Conscripts. It is not geared towards those who want to defend themselves in civilian situations.
A soldier is always armed when on the battlefield. His opponents are also always armed. Most importantly a soldier is always trying to actually kill his opponent. This can be the case for a civilian altercation if you live in america for example but if so why use anything other than your gun?
In addition a soldier has to be physically fit anyway to get into the army (even as a conscript). Krav Maga assumes a certain level of fitness for this reason.
Krav Maga techniques are fit for purpose in that they teach soldiers to react in an aggressive manner when threatened. They teach to get into a position where you can kill the enemy (often) with a weapon. This is not the goal in a self defence situation. If you are a civilian you want to get away not kill the opponent.
For this reason Self Defence is not a particularly rational reason for wanting to learn a martial art. Further, if you are at all likely to injure yourself in your training or in competitions then claiming you train for self defence is completely irrational.
Lets suppose though that you do want to learn to fight in a way suitable for civilian self defence. You just want to improve your odds of survival in the event of a particularly unlikely thing happening. Why would you want to learn a method intended to make you both aggressive and lethal and which will risk injury because of throws?
The attitude of the instructor you spoke to says it all. She was not interested in helping you learn to defend yourself or anything else. She just wants her students to feel tough.
To summarise I recommend you find a style in which to train where you can learn basic escapes, dodges and blocks without fear of injury. You won't be doing yourself any favours if you get injured while training. That completely defeats the objective of 'self defence' for anyone regardless of physical fitness.