Yes, you can remove any self-imposed limits from your account. However, if you have hit the set limit, you must wait until the limit is expired to do so. (Limits are set on a rolling 24hr basis.)
For example: If you set a 4-hour time limit and you hit this limit, you must wait until the limit is reset the next day to log in again.
To adjust your limits click on your account icon.
Depending on the platform you are using you will see a menu similar to the one below. Click on "Responsible Gaming".
From here you will be able to adjust all your self-imposed account limits including wager limits, deposit limits, and time limits.