"and my build isn't terrible but I'd like a boost to give me that motivation to keep at it"

Motivation shouldnt come from drugs. If after 10 years you dont enjoy training enough to do it consistently, then drugs probably arent a good choice IMO.

Query Harris Benedict Equation and calculate your BMR with and without activity.

Will you gain some weight during a cycle...of course you will. Will you keep that weight you gained from the cycle....most likely no. You are going to gain weight with a cycle due to the increased glycogen storage you will have on cycle. When the cycle ends, you lose that glycogen storage and all the weight along with it. Given your current stats and the time you have been in the gym indicates to me that you are not eating properly to gain the needed weight and keep it. You don't know how to eat right now to build lean body mass. Steroids won't make up for a subpar diet. You can't build something from nothing even with steroids. Running a cycle now without this fundamental diet concept will result in no gains after cycle and you will likely come out of the cycle in worse condition then when you started. You'll lose all of your glycogen retention weight and likely even more weight because now you have to suffer through a PCT with a shutdown HPTA and still don't have the fundamentals of a bulking diet in place.

This is a lot more complicated than just taking steroids and becoming "swole" as the kids put it. Steroids are a very small part in the grand scheme of things. If you were coming into this a good 20lbs heavier or closer to single digit bodyfat then I think you would be prepared and ready for a cycle, but you have a lot of info to learn and incorporate if you want to make your cycles a success.

yikes... Get bloods before, during and after your cycle if you choose to run one. Your pretty young...evaluate other options before taking the leep. Got motivation problems just wait till week 3-4 of pct.
Post your questions in the appropriate forums, take it all in, and try to make well informed decisions. Proceed slowly and with caution.

Bro you need a real diet plan if you want to get ANYWHERE in bodybuilding. 190lb at your height is way to skinny to be taking gear. With all due respect I don't want to hear the BS thing about genetics. Can genetics come in the play? Of course they can. So instead of bulking on 4000 cal a day you need to eat 5-6k per day. But it's not like gear is going to fix your metabolism lol. You'll STILL NEED TO EAT RIGHT.

I don't know bro, but if you've been in the gym ten years and haven't broken 200 at 15%, you have other things you need to focus on.

I think you'll be much happier with your results if you hold off on AAS for a little while.

There are good reasons to take AAS

to give me that motivation to keep at it.

I don't think that's one of them. At least I know for me I wouldn't be using AAS as a motivator. You want to already have all this down by the time you're ready to cycle.

My advice would be to stay natural another year. I'd cut first to get the fat down, and then eat, eat, eat, eat, lift, sleep, eat, repeat

So much knowledge to be gained here