Wow, that is a fantastic amount of sitting! I really admire your discipline. It's quite exceptional.
Keeping in mind that I am not a teacher (not even close!) and so what I say is just the musings of a random dharma bum, I would think that when you have that kind of capacity, it is definitely worth getting a teacher. If, for example, an amateur athlete were putting in that many hours, it would make sense for them to hire a personal coach. Same deal here. You are no weekend warrior (although your 10 hours on Sundays is definitely warrior level :-)).
My teacher, Nick (you can find him in that thread), is very good at teaching concentration, as he was a teacher trainer under Culadasa, the author of The Mind Illuminated, which is a book that many people have used to achieve high-level concentration. Have you read it? I actually have not read the whole thing, but I read the beginning and it seems to be very well structured. Another route to consider, if concentration is your bag, is the TWIM method, which also comes with teachers (although they are a little more religious than approaches like TMI). I first learned concentration from Leigh Brasington's book, which is also a good resource. Have you read that one?
Also, while it is pretty common (almost standard) for people to suffer more after they take up meditation, it just makes sense to find the path out as soon as possible, which is another argument for getting a teacher or at least joining a group. Have you looked at https://www.nyimc.org/event/new-jersey-sangha ? The New York Insight Mediation Center are good people, as are basically all the people in the Insight Meditation Society. We often diss this group here as being a mushroom factory (keeping people in the dark and feeding them bullshit) and while it's not untrue that they focus on a pretty low-level of insight in many of their teachings, they can be a great support for dedicated practitioners too, particularly in terms of day-to-day dharma.
I don't really have any experience with working with trauma but hopefully people here who do might be able to recommend some teachers who are skilled in that area.
You say, "I would very much like to improve my concentration, but I have quite a few attachments (my business, a college coaching job, etc.) that may be roadblocks."
I wouldn't worry about the roadblocks. I learned concentration while running a business. In fact, it was almost comical as the business got super busy right after I first gained access to the jhanas, so I was working 70 hours a week, and I had a cushion next to my desk so I could squeeze in sits during the day. Although some people go the lifestyle modification route, it is not necessary to have a whole life free of the hindrances to get concentrated. You just need to learn how to set them aside when you sit on the cushion.
You also say, 'I keep telling myself - “What’s the point in sitting if you remove yourself from socializing and enriching other people’s lives?”' I agree. In fact, even the monks in the Buddha's day had regular contact with ordinary people. It was baked into the system that the Buddha taught. Monks had to be part of the community by visiting people for food alms and talking to them about the dharma. Complete seclusion was not the preferred way even for these super-hardcore practitioners.
