What to do about having a closed off personality?

Over the years I've noticed that I developed a very closed off personality. I went through a lot of shit, and over time I've started hating humanity. I've become less talkative, find it hard to trust. I rarely smile anymore, and If anyone tries to make conversation with me the best I can say is "Hi" and move on.

I've been rejected a lot to the point where I've given up on ever finding love, so I make no effort to even have a conversation with a girl.

I can't help but see the bad in everyone and as a result I've been very alone. I have no motivation or the strength to carry on anymore.

Is there a point to life?