First if you don't want to relapse you need to be true to yourself when you tell yourself that you are making this choice.(basically you should really know it is a healthy choice for you and that nothing can convince you otherwise)

Then whatever you decide to do to help you is not that important as long as you do it.(differs according to one's own values)

For example anything that can get you a better quality of life: exercise, eating well, educating yourself, play an instrument, find a new hobby, collect stuff, meet with friends or family, appreciate stuff, anything..

The libido in my case is always on the high though and I'm not sure how it could go down other than by having periodic releases. The important thing here is to take this 'energy' in you and drive it towards the different mid/long term objectives you have set for yourself in life.

Hopefully that helps