Preface - I’m no mental health expert. But this is what I would tell a friend if they were in your situation:

You can take the L today and this week. Things in life can feel like mind-numbing pointless exercise sometimes, that is normal. Forcing a smile isn’t going to do anything about how you feel, and turning to vices (overeating, drugs, etc.) compulsively will only create more problems that are difficult to get out of.

Start by coming to terms with your feelings and that it’s a bad day or week. Give yourself time, space and a degree of lenience. You can be your own harshest critic. Write things down, complain to the aether, cry, whatever. Then, let your emotions be what they are and start focusing on what you can control. Even if work isn’t going well, you can prep yourself today or tomorrow’s meal, clean your living space, pick out tomorrow’s outfit, do shopping, check your mail or something else you might have put off. If you’re too tired, then you can work on fixing your sleep schedule. Today there are no bars to clear, no expectations. Get nothing done, or get anything done.

At your next full day off, try seeking out a small change of scenery or pattern. Take a walk through a nearby park that you don’t visit often. Buy a different kind of some grocery item than your usual. Take a bath. Give yourself an opportunity to reflect on your life, what you are thankful for and what you want from your future, however small or big, impossible or possible. Where on your priority list is the approval of your manager? Probably not even on there at all!

I know you will get through this downswing. If your emotion can’t be helped today, then all you can do is prepare for it to be even a tiny bit better tomorrow. Go get it, champ!

Here’s a different framing that might help:

Diabetics are normal people who happen to have a chemical deficiency that requires constant monitoring and chemical intervention. Some days diabetics will struggle to participate in society at all because of sugar level management.

You’re an emotional diabetic, just like me. I’ve got my emotional insulin tuned pretty well but there are still days where I struggle to find the willpower.

Give yourself the space and the grace to have down times, especially since you know during up times you’ll enjoy what you do. See if there’s any self care you can do to make the down times less bad.

Good luck brother/sister.

If you knew someone else was having the same experience as you, would you feel hate for them when they’re not able to get their shit done? If the answer is no then maybe knowing that can help relieve some of the self hate you’re feeling over your circumstances.

I suspect you may even feel inclined to provide empathy and support for the person having the same experiences as you. If that’s true, then you know people having your experience deserve empathy and support. You’re one of the people having those experiences so you’re deserving of the same as others!

@Roflmasterbigpimp well, I am not experienced in helping depressed people, but my naive idea would be, that you might be better if you try to program sth. That could give you a Sense of achievement.
I really enjoined doing advent of code last year, because you have easy but still challenging code puzzles and it has the social aspect of comparing and exchanging ideas with your friends, which is really fun.
If I missed the point of your sadness, maybe just know, that your friends are there for you

It is completely human to feel down from time to time, when you feel like something is missing then find a thing to fill the void with (no alcohol or drugs)

Also remember, there is no normal everyone is a individual and we are all different in our ways.

I don’t like to be one of the “just go outside” people but in your case going for a walk in a Forrest or another area of your choosing might actually help to get your head free from work and some physical activity (even just walking and looking at flowers on the ground or the Land itself) would probably brighten up your mood over time (bonus being that its healthy for the body as well) you can also use a bike if you like too.

Other than that I’d recommend cooking or baking, its good to do it yourself and you learn or improve a useful skill. Also its great to make something with your own hands and enjoy the product afterwards, while you can relax some other parts of yourself.

Playing some relaxing games might also help, the type is up to you of course, I’d personally recommend stardew valley, factorio or rimworld all are relaxing in their own way. When you have friends to play with that’s cool but its not necessary when you don’t want too.

My last advice might sound stupid but it helped me a lot to gain self confidence and self respect, wich I would say you lack from how your post reads. every morning and every evening you stand in front of a mirror and say something nice to yourself one thing every time (something like “today I finished XY”“i was very eloquent today” “I helped someone today” “today I look great as always” and so on), you wish yourself a good morning or good night and say something you want to do tomorrow. A important thing regarding this is that it works like a placebo and a self fulfilling prophecy at once, it will work even if you don’t want it too and you will care more about the small things you did right and you will improve yourself subconsciously without putting yourself under pressure. You don’t need to move the mountains, you only need to carry one spoon of it every day and soner than you realize the mountain will start to appear smaller and smaller. Getting out of a depressive phase or a depression takes time but you have that time you will outlive your depression and you will dance on its grave.

All of this helps regardless of the people around you, however if you have emotional distress talking to someone will help more, these things i said can’t cure trauma they can help living with it but when you feel overwhelmed talking to a doctor or friends or family about it will help a lot. And one important thing, its OK to cry.

Best wishes.

(Open for questions)