I can relate, I´m 18 too. As young men we have to find our place in the world and It´s not easy. Youth is the most difficult part in a young man´s life because we don´t have nothing to offer...yet.
I can also relate to the suicidal thoughts, I don´t buy into the whole "suicide is bad, you are a snowflake, bla bla bla".
Whenever I feel suicidal I renounce to my identity, to my expectations and plans, I simply let go of all of it, and a new playfulness arises, maybe I can´t do X at the moment, but I can do these other amazing things instead so who cares!
Hope it helps, hit me up if you want