From my humble experience, a tren cycle at this point in your career won't really get you where you want to go. Having done a tren cycle early on in my training was indeed a game changer. But I didn't add a lot of weight with it. I have a feeling that tren works best on a well trained body... On muscles that have matured with rigorous, persistant, training for years. Like you, I am an ecto-meso (sp?). Weight gain is difficult and tenuous. If I break from my diet, I will lose weight fast. So I agree, learning to eat should be your top priority. It's not just the amount of calories you take in, it's also what you eat, and when you eat it. Pay particular attention to your breakfast, and your post work out meal. Do not be afraid of carbs and fat... They permit us to perform strenuous workouts. And rest is equally important. Your muscles break down when you exercise and GROW WHEN YOU SLEEP. I've learned now to take a full 24 hours off after my leg day to do nothing but eat and sleep. And guess what, I now have impressive legs!
All that being said, a tren cycle now won't kill you. You will definitely learn something from it. Just do diligent research because tren has some weird sides you might not anticipate. But don't be surprised if you actually lose weight. Especially if your diet is not spot on.
While you are learning how to train and eat and rest for mass (and yes this takes years... Every body is different and you have to know how yours reacts to all kinds of stressors), I think you'd be better served by compounds like test, deca, and d-Bol. Temporarily suspend your fear of fat and carbs. Back off the cardio. And actively persue the art of rest. You might research EQ... It really makes you hungry. Also, resist the urge to take massive doses of anything. More is not always more. I love what a gram of test does to my head... But it doesn't make me bigger. 500/week seems to work better for mass... Go figure?
This is my own experience. The muscle game is all a big experiment anyway. I'm sure you'll get to 200 lbs soon enough. Try stuff and see what works for you. Always listen to what YOUR body is telling you. You'll figure it out.