I would suggest running instead of going to the gym, no time limits, few excuses, you can always do 100 pushups, squats, sit-ups.
One advice I had previously when I was unhappy/depressed after neeting for a few years, I blamed myself but when I had a real job, I could at least blame all my troubles on my job and I think that is what 70% of ppl do, work sucks, but that is life, if was a great relief to join reality and blame something else and not yourself.
Who knows what will come tomorrow, but will you cry if it rains, i doubt it, take life as it is, a bunch of organisms competing for resources.
Alcohol makes you lucid and allows you to think, it also digs a hole, you keep digging a hole you feel warm and safe after a number of years you might not understand the world but you know you will feel warm and safe in your hole.
So any stress, anxiety or boredom brings you back.
However life is full of anxiety, stress and boredom.