By the end of Sunday each week, starting with this week, spend at least 45 minutes on membean. Take advantage of the various ways the site helps you own your new words.
Also, pace yourself, so that you spend 10 or 15 minutes during each learning session during the week. You will learn these words, and be able to use them, more successfully, if you develop this habit. The quick-I-have-to spend-forty-five-minutes approach does not work nearly as well. It will exhaust and exasperate you.