they are giving you good advice. On your current diet you will not gain. You should be able to grow on cycle or off cycle. If you are not growing now you wont grow on cycle. Any gain you might make you will lose because you caloric intake is too low. When on cycle you need you intake to increase even that much more.
My suggestion would be.
#1 wait till you are older than 21 you still have natty test you can use to get bigger. Ideal is 25.
#2 EAT. when you can show you can gain naturally then you will know you are more on track with diet. Talk to 3j in the diet section and he will help you out.
#3 Stop running so much. That much cardio and exercise is not conducive to to what you are trying to do. Scale back the cardio to 1 day then week heavy lifting now rep. there is a good 5x5 routine in the training section might be good for you. If you over work and don't give yourself proper recovery time you wont grow.
#4 Learn to listen to others. If these guys say wait. THEN WAIT. If they say you can gain another 40 naturally. THEN YOU CAN GAIN ANOTHER 40 NATURALLY. There is alot of experience on this site. Believe it or not they are trying to give you the best advice possible. There is alot of risk if taking steroids. You can really screw yourself up. None of us want to be of testosterone replacement therapy (TRT) for the rest of our lives. If you don't know what testosterone replacement therapy (TRT) stands for.... That leads me to my next point.
#5 READ. You have got alot of reading to do. I'm pretty new to this forum but i already have a couple of hundred hours of reading on here and i still don't understand it all. READ. READ. READ. start with steroid profiles. Learn what your drugs are. AI's, Dope antagonist, PCT, HCG. Learn why to use it, how to use it, when to use it. Estrogen sides, prolactin sides. Go to the diet section figure that out...... ECT....... You have along ways to go before you ever start asking about dosages. Honestly you should put in about 3 months of research and studying before you even think about taking anything. During that 3 months you could put on alot of weight naturally.
For your first cycle though...... most just run test. You don't what cycle that can give both estrogen and prolactin sides and not know what is giving you what. take it in steps. Ok i have said enough.... I have done my part in your education.
as the good book says. i hope i'm not throwing pearls before swine.