Sadness

Hi there. This is quite mad but for a while now I’ve had this feeling often. Basically like a big shadow of sadness and it feels like a weight on top of me. It keeps me quiet and shy sometimes and even nervous. I don’t want to speak to anyone in person because of embarrassment to be truthful. Is there any quick fix to this sort of problem ? Every night I go to bed and I sit there pondering thoughts of death and I’ve fantasised for a while now of leaving away from everything and starting brand new. How does one go about resolving an issue like this? It’s not too bad I wouldn’t say but i don’t enjoy feeling sad