I used to be depressed and suicidal. Had a dark point during uni. I worked it out in the end, and gained a better perspective on life.
Emotions are like a river. If you try to contain it for too long, it'll overflow in any and every direction. If you accept it as is, it'll flow in the right way, and leave that way.
Some things that will help:
1. Accept your emotions.
2. Use music to cope with a feeling. Sad music can make one's sadness go away. Angry music and take the tension away.
3. Learn to truly love yourself. A lot of people don't do this. Once you have self respect, you'll be around people who you genuinely enjoy.
4. Embrace Stoicism and Epicurean philosophical ideals:
Stoicism:
Our fate is in the hands of God. We cannot change our fate, but we can change how we feel and embrace that which we have control over. Ex. If someone is pissing you off, you might get angry, but is this the most sensible reaction at all times? No. You must ask yourself: can I stop him from annoying me? If so, act on that. If not, abandon that man, as he is worthless to you.
Epicureanism:
Embrace that pleasure is the greatest good, but not through an over consumption of pleasure, but through the avoidance of pain. Certain goods are illusory. Power can never be truly gain. Wealth can never be fully gained. Fame is fleeting. Only concern yourself with the tangible.
5. Accept that the only emotional state you can know for sure is your own. Do not guess the feelings of others. Do not believe your actions do anything for others. Only do things for others when you genuinely want to.
6. Never be overly attached to someone you barely know. Make them earn your attachment. As they do not know you, and you do not know them, being too overly nice or rude will do nothing for you. Also, this can help avoid a lot of headaches with people.
7. Live for yourself first, and settle your problems. You may believe this is selfish, but it's actually more selfless in the long run. Allow me to explain:
-As you continue to help others before you help yourself, you'll become more and more burdened by your mounting problems. You won't be able to handle them all.
-If you handle your problems first, or at least prioritize them, you can then be in a state of calm and with more than enough time to assist others.
-You cannot take care of others, if you do not take care of yourself.
I hope my advice genuinely helps y'all.