If you're not willing to work hard, let someone else do it. I'd rather be with someone who does a horrible job, but gives 110% than with someone who does a good job and gives 60%.
Sex is difficult, yes. But they are difficult things with which we have been charged. . . If you only recognize this and manage out of yourself, out of your own nature and ways, out of your own experience and childhood and strength to achieve a relation to sex wholly your own (not influenced by convention and custom) then you need no longer be afraid of losing yourself and becoming unworthy of your best possession.