Julian, honestly, give yourself and your back a break - even if it may break your heart for a while! Listen to your body and give it time to heal itself, do not try to speed up the process. Your back is one of the most sensitive and injury-prone areas in your body and should be respected like you respect your girlfriend
No, seriously, you can up on glucosamine but it will not make a huge difference. What I can suggest is the following: STRETCH! Sorry for shouting but I needed to. Bad posture and a lack of stretching are the main culprits for back injuries.