How do i get logan to love me more or get one heart
Make sure that you didn't encourage him to go to the bandit camp after the attack on Bareshade. Then, during the werewolf event, go after him instead of after Bernard (it won't affect your ability to get likes or hearts with Bernard).
There's a way to get a 2nd heart after you help Bernard build more houses in Bareshade. Logan will visit you and get drunk. Don't have sex with him while he's drunk or he will convince himself that you tricked him and hate you for it.
It's a slow romance, but then so was Bernard's in the beginning. Now we can fuck every night.