How can i sing better?

Ok i am a drummer for a band that i have. Our band is a reck right now because we dont have the right singer. All we really have is me and this other guitarist. I am also a guitarist that write songs for this band and i am the only person who writes for this band. I feel that i need to show the band my song writing talent by singing with the songs i make. But i just cant sing. I cant articulate right and i need help. I am on a very low budget so no lessons. Example is that i cant sing high notes like those fake girl voices anymore since i turned 14. Not only that, but i think my singing tone is bad. To me it sounds like a kid voice. I really need to improve on my tone and singing. I really need help. And to make problems worse, my parents dont know that i want to sing . I dont want them to know because they think im a person who doesnt sing. But when i have a good voice, i can show them that i can sing good and surprise them. So please, i really need help.