To ATP Alexandra!
I don't have a good answer for you either but from the sounds of your post you're already off to a good start with a career in the field of your liking. Best of luck! I completely understand your question. I pondered the same in my late 20's with a client list that consumed for than 40 labor hours per week. Scheduling, billing, and more were all done in the wee hours. My only "free" time. We have a great turf management program here through OSU. Didn't appeal to me due to relocation and actual subject matter. Landscape Architecture seemed to lean towards the drafting and engineering that didn't really appeal to me or my plans for a career. It would have been a great choice as would be a lean towards horticulture. Given the choice today I would be asking exactly what you are, betting some folks with more to offer will chime in as days go by.
I know myself well enough that I'd likely be doing exactly what I doing now working the labor end. With your age, experience, and enthusiasm any of your choices will give you options. I've known folks with degrees in engineering to make good in the field in regard irrigation/drainage and even particular plantings associated. Working with concrete companies and landscapers just the same with other options that are always in demand.
Again, best of luck!