You're getting conflicting advice because the 800 is an in-between event. Metabolically, it's really different from the 400 and from the 800. Arguably, the 800 is the only track event with no other event really like it. Your own performances reflect this. Competitively speaking, your 800 PR is much better than your 400 or especially 1600 m PRs.
So, the sprinter-oriented 800 meter runners think that you just need to run cross-country for endurance then sharpen with intervals the rest of the year. The distance runners, following a classical Lydiard framework, think you need to work on your base then sharpen later in the season. From an energy perspective, the 800 is almost exactly 50% aerobic and 50% anaerobic (5% creatine phosphate and 45% lactate). So either approach could work, depending on the runner.
From what I see, your training makes sense for an 800 meter runner at this time in the season, but you need to slow down your repeats. Start the 400s at 77 then work your way down over the workout. For the 200s, don't focus on the time, so much as "good swing" and "good speed" (look up Johnny Gray). Your total mileage is fine for 800; you may want to gradually bump that to 35 over the next few months. Relatively speaking, your endurance is the weaker component so slowly adding volume is important.
Three workouts a week is fine but you need to run them at an intensity level you can tolerate. Don't perseverate on interval times--the point right now is to get in a good volume of hard work. With three workouts a week, you won't be able to run any of them at max capacity. You'll be too tired. Later on, during the season, the workouts can have more recovery and you can blaze the repeats to build confidence. The main thing now is to have faith that the volume of work will pay off even if the repeats themselves aren't as fast as what you remember doing last season. It's really hard on the body to put in the work and runners doing the right amount of work often see regression the first month or so due to tiredness.
In my own experience, my senior year of high school, I finished the indoor season with a 9:42 2-mile. I rested four weeks, put in 5 hard weeks of training, and started my outdoor season with a 10:42 3200m. I didn't sweat it, just kept pouring in the work, and managed to chop that down to 9:30 within ~7 weeks (a recovery week just before this made all the difference).