Address problems now, while they're still relatively easy to tackle. Leaving them means they will build up and be harder to face.
Adjust your work life balance. This means doing things like (as have been mentioned) getting more exercise and getting better sleep. Both of these will not only help your mood, but they will make you more productive.
You need to talk to your team. Explain what's happening.
You have awareness and insight - you say "despite things going well I'm somewhat depressed" - that's good. Try some cognitive behaviour therapy techniques. A good book is "Mind over mood"; a good website is the Australian "mood gym". You could see a therapist.
Luckily this kind of stress / low mood responds excellently to interventions.
Adjust your work life balance. This means doing things like (as have been mentioned) getting more exercise and getting better sleep. Both of these will not only help your mood, but they will make you more productive.
You need to talk to your team. Explain what's happening.
You have awareness and insight - you say "despite things going well I'm somewhat depressed" - that's good. Try some cognitive behaviour therapy techniques. A good book is "Mind over mood"; a good website is the Australian "mood gym". You could see a therapist.
Luckily this kind of stress / low mood responds excellently to interventions.