Hey brother, I started at 250 pounds and within a year got down to 180. The quickest, easiest answer that's an overnight fix is to buy into the culture. There are countless stories of people overcoming barriers to achieve great personal milestones through the platform of jiu jitsu. It sounds like you've taken the right steps by working on your diet and joining the forum. Continue to listen to your instructors, learn from your instructors, invest in a game that is mechanically and ergonomically efficient. I can't stress that enough. Pedro Sauer is a big proponent of investing in a type of jiu jitsu that is safe on your joints. Stay within your ranges of motion, minimize the will to win and replace it with a will to learn. The greatest obstacle I foresee for you, as was for me, is to get over the ego. Understand that by using strength and aggressiveness to get by, you may in fact get the results you are hoping for, but there is no quicker way to, as you put it, stick like a "sore thumb." Accept that today, you may deal with some injuries. These injuries may threaten to set you back and slow your progression. Use those times to study the movements of the upper belts, and continue to invest in your knowledge. If you do, I guarantee personally you will come back a stronger grappler than before.
Short answer to your question: if you commit yourself to knowledge, asking questions after a round, and safe mechanics, you will flourish. If you commit to winning, you will be your own worst enemy for your development; physically/mentally/emotionally/spiritually.