i was like you at some point in my life.
I've been in your boat: tall, long arms, fast metabolism

All i can say is eat, eat, eat. Everyone thinks they eat alot until they meet someone who really does eat alot.
I thought i was a hardgainer, thought i would never be able to put on mass. I was training very hard, but i was not fueling my body right, i was not taking in enough calories.
And don't look for huge jumps in bodyweight, just focus on gaining 1lb a week. It doesn't seem like much, but in 3months that's 12lbs. It adds up quickly.
Good luck man, oh and eat,eat,eat


You have a nice frame, and you would look pretty damn good at 220lbs,