Should i constantly worry and ruin my life over getting pregnant i take birth control pills perfectly?

Paranoia: Yes. You should. The reason one goes onto birth control is so that they can relax about worrying over the risk of an unwanted pregnancy. You did not mention what type of birth control you are using. But, most are very effective at preventing pregnancy if used correctly.

STD worry: Since you are 18yo and likely single and not monogamous your 'worry' probably has at least one root in the fear/worry of contracting an std. If this is contributory i would suggest your sexual partner use a condom. Bcp's do not prevent std's.

No: Take the pill the way it is prescribed. Take it perfectly as you say and live your life normally.

Birth control.....: Modern birth control, grounded in a detailed understanding of the endocrine axes controlling ovulation and pregnancy support, is indeed quite effective, but it is not perfect. There is always a chance, albeit slim, that you can become pregnant if you are sexually active. My advice to anyone, man or woman, is not to engage in sexual intercourse unless you're ready to accept the responsibilities.