What are things I can do to volunteer and help out the service which has helped me?

SPC RIELLO, you mention that you are a "soon to be high speed Sergeant". A Noncommissioned Officer is supposed to be a Leader; otherwise they are just a "stripe wearer". I challenge you to be a Leader.

You are not truly a Leader unless you are followed somehow. If you have peers and/or subordinate Soldiers within your unit, mentor and guide them to greater levels of success. That's a great way to start.

You also mentioned how the Army has helped you so much. Do you know any young men or women who could also use help? You seem as if you know what it takes to be a Soldier. Find young people with a genuine interest in wearing the uniform to share your story(ies) with. Who better to help someone become a Soldier than a Soldier?!? Share with them what will help them most initially - studying for and scoring well on the ASVAB and obtaining/maintaining physical fitness. Those two things alone would put them ahead of many.

I hope my response leaves you with some ideas.

Slow down, strive to emulate those you admire. Listen, learn and be modest. It will all work out. Steady!
High speed? Your profile indicates you missed a turn or took a few detours in attaining SGT E-5. Steady!

Give to the service support/relief fund. Volunteer to be a DD for unit functions. Take a young hard charger under your wing and share your "high speed" tips for promotion and success.
I'm sure there are plenty of volunteer opportunities if you look around.