How do you stay motivated in a thankless job?

First, you have to like what you do. Which service won't matter. If you need to cross train shop around first. Have your First Sergeant make arrangements to visit some shops you might be interested in. Try one on for a day and pick their brains. Don't jump unless you know what you're in for or what you want.
Good luck with your decision.

I recently cross trained from munitions maintenance to Command post (command and control). I completely understand what it feels like to be unmotivated and in a thankless job or at a least a job that the thanks feels sarcastic, and never seeing the end result of your work. My advice to you would be to first determine if you want to stay in or get out of the Military. Do you not like your job or do you not like the military? If the first, find what you like to do and then try to cross train into it. If the latter, find what you want to do outside of the military and work toward preparing for that if you are not ready already.

Like the individuals wrote below, it really does help when you have a team of people that you really enjoy working with. I know from personal experience how that can really change your outlook on your job and life. Does this mean that I don't notice things in my new job that could be better? Of course not. But they pale in comparison to what I came from.

Don't let anyone tell you what you should do with your future. Take advice from everyone but you do the research and find what you want because at the end of the day when the lights go out, you are the one that has to face it all over again in the morning.

When you look at the list of jobs on MyPers to cross train into find ones from the list that you would be interested in. Only choose those that you know you would like. Interview individuals. Ask them what is the good, the bad, and the ugly about their job. You want to know what they love and what they hate about their daily tasks. Weigh your options. For my job interview most of the complaints were that it was long hours and they were stuck inside with no windows. Compared to what I had at least I wasn't facing twelve hours in the snow holding a shotgun and flak gear.

What do I wish I had done differently? I wish I had been able to talk to the airmen one-on-one about what they didn't like or did like. I didn't realize at the time that they did not want to tell me the full truth in front of their superintendent. I wish that I had been able to shadow someone for a week on the job. So far those are the only two things I can think of that I would have done differently. Do I regret my choice? No, honestly I don't. Even though I have recently been going through a rough spot with training and everything else on my plate, in the end it has really been worth it. My outlook on everything is so much better. I don't come home hating my job. I have a great team that I work with day to day. My supervisor is the best supervisor I have had. The options for this job are endless compared to my last job.

Meet with your career advisor and get to know what options are open for you. Kudos to you for looking ahead for the next two years. Keep your chin up.

We get this all the time where I am - junior leaders tell us senior NCOs that they don't know whether or not their products are useful. I'm in intel so it kind of matters to know whether or not a product you work on for days actually made it to the commander or not. A lot of people (military and civilian) are kind of disgruntled here.

I was going to do four years - I hit 13 in July. I was the one in my group of friends in basic who was getting out and everyone else was retiring. I think I'm the only one from that group still on active duty and one person is NG still. Everyone else got out.

I've heard this pretty much in every unit I've been in whether an Army unit or the two joint units I've been in. I have had people who a certain unit was their first unit and they judged the Army on that. I always tell anyone - any service - to at least try one other unit before making a decision to get out. You can't judge the military on your first unit.

I'm staying in because of my daughter in all honesty. If she didn't have the medical condition she has I think I would have probably not reenlisted last year and gotten out this year in August like I was supposed to. But I'm also so close to 20 that I may as well just keep going.

I've liked most of the things I've done. There's one unit - my last one - that was the most toxic, horrible units I've ever been in. That unit a lot of people said "I was going to stay in until I got here." Thankfully it no longer exists.

If you think you want to get out you need to look at all your options and you better have a plan for if you were to ETS. Too many servicemembers don't plan for after the military. Also realize that people feel like this in the civilian world too. It can happen at any type of job.