I would recommend removing your 3 points in Survivor's Scars to put them in your Sawbones tree, and build from there. Once you have 31 points spent in Sawbones you can start spending them in the 2 other trees. That's what I did, but it's just a personal preference
Edit: Just some quick reminders, always keep at least 1 stack of Upper Hand, always spam Diagnostic Scan when you're not using your other heals, if you go below 50% energy start casting Diagnostic Scan to bring your energy bar back up faster. I probably forgot some other things.