How to stop with the negativity?

I have realized that I talk crap about others a lot. Not to their faces, to people I trust. I don’t want to be that person anymore. I tell myself everyday I’m not going to be like that, then by the end of the day I find myself talking shit about someone 🤦🏻‍♀️ even though they deserve it.. I know the people I talk with don’t want to hear my negative talk. It’s like I just have to vent... but I know they don’t want me venting to them all the time like this. How can I help myself better?