I carelessly gave a stranger my account password and now he is using all of my crystals to buy unwanted things.i cant change the password because im playing in mobile version and there is no option

In the mobile version after the recent server maintenance on march 25 2020 i cant enter the match after battle is found.this is because the 'remaining' on the top right of the waiting screen decreases to 1 really slow.even if it reaches 1 im not able to enter