even when I'm not sad and dont have a reason to be sad the heavy feeling in my chest is still there constantly.

This means it does not matter what you do, you will be depressed, whether you stay at home and play vidya and goon, or go outside and accomplish something, but at least with the latter you achieve something. You will still be depressed, but you might alleviate it a little.

This is the best mindset to have. Consider the tale of Orpheus. He went to the underworld to retrieve his wife from Hades who said "you can lead her out of the underworld as long as you don't look back until you are both out", however the moment he exited the underworld in his haste he looked back, while his wife was still behind him and still inside and just like that she was sucked back in. The moral of the story is debatable, but Orpheus looking back reminds me of myself stuck in the past, reiterating memories and feelings in my head over and over excessively. You have to let go.