When Thor loses his hammer, he believes he is no longer as strong as he was because he lost his powers as the God Of Thunder.
Odin comes to him in a vision (twice) and shows that the hammer "was to focus his power". We first see that Thor has the powers of thunder within him when he was being battered by Hulk.
When Hela was about to kill him and asked him "What are you the God of?" Odin came to him and told him he has the powers of the hammer inside him.
If this is the case does he lose certain powers because he no longer has it with him physically?
At the start of the film Thor is seen placing the hammer on the jaw of the dragon and causing it to be locked down on the ground because as we already know 'those who are worthy can only posses the powers of Thor'.
Thor has been seen before at other times placing the hammer on villains to stop them from moving.
Without his hammer how will he do this? Or does he lose this power?
Another power he had was to control his hammer psychologically, for example when in the Sanctum Sanctorium he calls for the hammer and it travels to him (while smashing a few stuff) and he has the power to stop the velocity of the hammer mid-air for example when fighting Surturs minions the hammer is seen flying in circles then decelerating and returning to his palm at command.