Welcome to the board and to MURPG!
There's lots of different games going on. Some allow you to take a canon character and build a CAD based on that concept and others allow you to create custom original characters using the ruleset.
Well it's not surprising to hear you ran into energy issues as a new player.
The energy 'spiral' can be dangerous. For example if you regenerate 1R per 1W health, if you get damaged in battle, that means you get less energy the next round.
Ways to overcome this include, mutant healing, regeneration, picking energy efficient actions, or taking no stone actions for the turn!
Mutant healing is self-explanatory. For those who regenerate energy based on health, returning the health will boost their stone regeneration back to original levels.
Regeneration includes things like healing factor, accelerated, enhanced, and even instant. This boosts stone generation to 1.5x durability and for instant 2x. So characters who invest in this modifier will have more energy stones to play with per round! On top of that they heal up health themselves given the appropriate amount of time!
Picking efficient actions include actions that give a free bonus or actions that cost little for the effect.
Example force field gives a free bonus modifier. You put in 3 stones to forcefield, you get 6 stones of defense. That's doubly efficient!
Or a character who has ranged attack and targeting. Let's say their Ranged attack AN is 4, their rifle has a weapon modifier of +2 and they have targeting modifier of +3. They spend 4 stones into their ranged combat action for 9 stones of ranged damage! Now that's efficient!
You can also do things that cost little to no energy like trying to hide, run away, 'talk the enemy down' or 'distract' with social skills, etc. The only limit is your imagination!
Finally there is INT regeneration. Technically a character who uses optional INT energy regeneration does not regen based on DUR but based on their INT stat. So taking health damage shouldn't reduce stone regeneration.
Some GMs rule that health damage still reduces your energy regen though, so this might not always apply!
Don't forget that energy management can be cooperative. Maybe one player goes all out on one round while the others rest or take efficient actions. Switch who is going all out so you don't all end up exhausted at the same time! Also remember that the enemy has the same energy restrictions. Eventually they will run out as well, if the players smartly managed their energy!
Hope that helps. I recommend that you jump into a game here and find out for yourself.
Good luck, and have fun!