Work on improving yourself, not for anyone else but for your own confidence of accomplishing something.
Exercise every day, eat healthily, study hard, work hard, find a new job, learn a new skill, carpentry, a musical instrument, a martial art, a sport, a foreign language.
Join a club, samba dancing, or a foreign language club. One that is social.
Start hanging out at the same cafe or library regularly, you'll become comfortable there and chat with people, even make friends.
Worrying about not having had sex isn't the way to go, just start living well, things will come.
Sex isn't a big deal either way, you'll realise that when it happens.