I'm a blue belt with three stripes now. My real training time amounts to three or four years ( I don't count time spent away from the mat like injuries, long layoffs, vacations...etc), doing BJJ at least 5 hours per week; sometimes more, sometimes less.
I'm a little above average height-wise, and definetely heavy. I now weigh around 200lbs at 12% bf and 6'1. I've been as high as 235lbs before BJJ. When I started this thing of ours I was 220. I had never done sports save for kiddies karate and the occasional summer activities like kayaking or trekking. If you had asked me at 18 to show my guns to some nuns, I'd have nothing to show; my biceps wouldn't bulge. I was, and am, uncoordinated, slow, clumsy and insecure when it comes to the awareness of the body and how to move it. Being this heavy, and not wanting to hurt my training partners during practice, I'm sure I have done a lot of bad reps thinking that, if I did them properly, I'd be hitting them too hard with this body of mine. The first step of sucking.
I sucked for a long time, and I didn't compete for a long time. I was still thinking I sucked big time when I was awarded the blue. It happened again with my first stripe. The game started clicking by the fourth stripe at white, which meant I developed more as a defensive player since I was mostly reacting or resisting instead of acting; I had partners that made sense of the whole shebang from day one, and they developed an attacking style. As a white I'd tap some other white maybe once every several months. As a beginner blue, I'd tap some white every week. My fellow blues, maybe once a month if I was lucky. Life happened and I had to move to another city where there wasn't any affiliate of my first team, so I had to change teams to keep practicing.
I have competed a lot more since I had to change teams, and rolling with new people has made me improve much faster, and made me realize I don't suck as much as I thought. I sucked for a long time and I thought I was banging my head against the wall, but it unknownlingly paid off later on the journey. Dilligence, patience and open-mindedness are key while you're training. Swimming new waters, be it by competing or trying new things and letting others try new things on you regardless of being tapped out, make for some essential complimentary work.
Just don't give up, sherbros. It'll all make sense eventually, and eventhough I'm far from being anything resembling a succesful low level athlete, I'm enjoying the shit out of this thing of ours.