Use force host in your binds? If you need me to add it to your patch tell me. Also you could try getting everyone except for you to hold X, it cancels them out of the host selection.
i always just go to barebones with 3 other people and they hold x and if im not host for some reason i get host to leave until i am, then i invite the others till its a full game
With the new mod menu you can start in private match and change it to online after a while. End the game and you will be in pub match and will be host, or do as the other 2 posts state they are good answers
to make it easier to get host make sure u have all your ports open/port forward (youtube how to do it), and have good internet, thats allways handy and use the force host dvars
hope this helps