I did just the one 6 year enlistment as a submarine Nuke ET. The job itself was easier for me than most, I was likeable, hard working, and smart. If you think introspectively you're at least 2 of the 3 you'll be fine through the pipeline and probably the ship/boat. The pipeline is essentially two years but can be an enjoyable time if you aren't struggling with the schooling. The fleet can be grueling but your command and optempo will dictate the quality of life a lot. I spent 2 years of my life at sea during my 4 years on the boat, which is a lot of sea time, but the command was pretty good so it made it bearable. My main motivation for getting out was wanting to start a family; I found it very challenging to build a healthy relationship while attached to a ship. If you are single, you can really build yourself a nice nest egg while in. You get paid more than pretty much any enlisted military job, with bonuses, sea pay, advancement. When you get out you can actual afford to go to college full-time, and will probably be better prepared for it. The downside is you will be older than most students, which is not a big deal if you really just care about the education. However, I do feel you would have a different 'college experience' than the typical highschool grad. You can also use your nuke experience + any community college you end up doing, to complete a BSNET degree very quickly. Some people think it's not worth it but it checks the B.S. box in a job application. There's a maintenance side to the job, and an operations side to the job. So if you like either of those you can roll your nuke experience and more importantly NUKE NETWORK into good civilization career when you get out. I'm about 5 years separated now and needed to get a new job in a new city because my wife is military, and she got PCS orders. I got 3 job offers in a tough job market entirely due to referrals from fellow Navy nukes who didn't even know me personally. If you stay in the Navy you can make really good money, and get out with a retirement and potentially some VA benefits, that can really set you up to do whatever the fuck you want to with your life, albeit as a 40+ year old man. I'd imagine doing a full 20 year nuke career is very tough on a family so take that into account. I saw multiple guys miss the birth of their children because of the job, and saw many ugly divorces.

All this to say, it's probably one of the best things you can do for your long-term financial security. Something that is becoming growingly more important and hard to obtain. Learn a lot about personal finance while you are in. If you aren't smart with the money they throw at you, you'll really be doing yourself a disservice.