Will I be stuck as an 11b after recruiting duty?

By the time you finish your assignment you will be an E6 with 9 years in the Army, Recruiting is a 3 year tour. You might even have a chance to reclass, you might not. Most likely whatever dream assignment you have in mind won't have any class seats, and if you do reclass you will probably regret it and miss the Infantry.

You only know the tactical portion of being an Infantryman, but not what the Career of an Infantryman is. Your idea of the Infantry is fire teams and squads going out to the field, shooting and getting dirty. But think back to how often you saw your Squad Leader, PSG, and 1SG out there sweating in dirty. Your career as Infantryman isn't all kicking doors and shooting.

The general career path for CMF11 once you hit SSG is to move back and forth between Force Generating Assignments and Operational Assignments. You'll do three years in Recruiting just in time to return as a Platoon Sergeant (if you've had your SL time), then head off to another broadening assignment like OC, or EOA, possibly a year or two of staff time in an S shop in between assignment. By then you are about 15 to 18 years in and looking toward MSG. You pin MSG, take over a 1SG position for a few years and then move to another broadening assignment like a school house or work in a higher level shop again. Boom, you're at 20 years and on your way to SGM and CSM if you choose.

Yeah, I think it's all a conspiracy the way they get people to convert to 79R

Talk to a retention NCO and ask about any MOS’s that are available to SSgts and above. I am sure there may be a few options there. In the Marine Corps there are several jobs that open up at SSgt. You can also brain storm options while talking to the retention folks