You should absolutely go see a doctor. The problem with ergonomics is that everything is bullshit. For instance, you know that famous thing where all your joints should be at 90°? Yeah, not so much. My cubital tunnel symptom was because my hands were too bent. Putting my keyboard deeper into the desk helped. Similarly, your issues with the shoulders don't sound like anything garden-variety, but then again they might be.
If you would like to hear anecdotes, here's mine. I was a horrible typer (spacebar with my index finger etc.). I learnt Programmer's Dvorak, which helped me type more sedately/less spastically. But it was still on a full-sized keyboard. More recently, I switched to the Ergodox EZ, and I definitely prefer it. It sits shoulder width apart. I found out I prefer NOT to have it tented, as my desk is too high already, and it would lead to pain on the top of my wrist. I also changed my keyboard layout to basically ignore half the keyboard, and just stay on the home row as much as possible. Fn keys, the thumb cluster etc., I try not to use at all. All of these things helped. But what helped most was going to a doctor, she measured my nerve speeds, and recommended a strap to wear at night. So, go to a doctor!
To be clear, my shoulder isn't really painful just tight. It's the same with my wrist, everything in my right hand feels tight.
For example, on my left hand I can stretch my fingers back without feeling any tightness, and on my right hand I can feel a stretch when I do the same thing.
I will go to a Doctor, I think I've been putting it off too much thinking adjustments made at home would cure it. Sadly, some have made it much better but it still ultimately returns, just slower than before.
If you would like to hear anecdotes, here's mine. I was a horrible typer (spacebar with my index finger etc.). I learnt Programmer's Dvorak, which helped me type more sedately/less spastically. But it was still on a full-sized keyboard. More recently, I switched to the Ergodox EZ, and I definitely prefer it. It sits shoulder width apart. I found out I prefer NOT to have it tented, as my desk is too high already, and it would lead to pain on the top of my wrist. I also changed my keyboard layout to basically ignore half the keyboard, and just stay on the home row as much as possible. Fn keys, the thumb cluster etc., I try not to use at all. All of these things helped. But what helped most was going to a doctor, she measured my nerve speeds, and recommended a strap to wear at night. So, go to a doctor!