But I wish I could write you a list of thing mum. A step-by-step guide of exactly what you need to do to stop feeling unhappy. But I can't, because that's not how unhappiness works. There are certainly things to do to brighten up the days a little bit. But, really, there's no trick to simply get rid of unhappiness, or swallowing yellow paint just to brighten up from inside.
But what I did before is to be kind to myself, and being kind to myself means a lot of different things. It means being gentle with myself and doing everything in control to keep yourself comfortable and healthy - getting enough sleep, taking time to rest when you need it, going for walks, travelling, eating well, most importantly letting go. Being kind to yourself, especially when you're unhappy can also mean being hard on yourself. Refusing to let darkness win, getting out of bed and fighting against misery no matter how sad you feel internally. Forcing yourself to exercise, even I know you hate doing them. Reunite with your old friends that you used to laugh hard with - because you know, deep down, no matter what you feel like doing on the surface, that what you really need is to find back yourself.
You have to do these things, these harder things, when you're unhappy. You have to be strong, you have to love yourself, You have to tell yourself, YOU'RE HAPPY, repeatedly, every single day, even if you don't believe it. You have to keep moving, you have to keep going. And don't worry, you're not wrong for being unhappy. You're not a freak or a failure. You're not lazy or seeking attention. What you are is a person, and as a person we experience painful, almost-crippling bouts of unhappiness. Sometimes there is a reason for it, sometimes not.
But all you need to remember is that you're human, you're okay, you're not wrong for feeling this way. You have to be kind to yourself, you have to be kind enough to be hard on yourself. And most of all, you have to remember you're not alone, you're never alone, and this is exactly what connects you to every other person in this world.