Is this a self confidence issue?

idk what's wrong with me i always think people are going to laugh at me i used to have dreadlocks and i used to think people would laugh at me so i used to make comments about them like man ur dreads don't get on ur nerves sometimes but idk why i used to do that and people stopped wearing baggy clothes so wheneva i wore baggy clothes i would ask people do this look ok or not. this is the thing i don't really care about my clothes and things like that but i always think people will laugh at me so i guess that's why i do that but by me doing that people are going by my vibe and laughing at me because of what i'm doing. and i recently sleeped with a girl not bragging but the reason why i'm saying this is because i'm real quiet and people used to say i was lame and boring so i used to say man i need sum p*ssy no disrespect to women because i'm not like that but when i got some i starting acting like i was real talkative and like i was the sh*t. i really hate myself for this because people are really getting the wrong image of me, girls say man you're so emotionally and sensitive how you let a B*tch change the way you feel about yourself and my friends think i'm a punk/p*ssy over something else. Man, i don't even know who i am because i really don't know because i always fear people laughing at me i know we all make mistakes and gotta learn from them but this is really getting to me that i would portray and put myself out there like that just because someone might laugh at me or because of what they may think or may think, what do i do? i'm 19 btw