Alright they mate.Sorry to hear about your backache mate.Obviously u'll need to calm the heavy weight lifting for awhile.Lower back pain can really effect your every day life when it's in really bad shape,I know i've been there and it's not a nice place.Get an appointment with a physio and let them know where and how the pain is in your lower back.Whatever you do do not do NOTHING,unless it's a major injury which by the sounds of it does'nt.You'll still need to do stretches in your own time about 3 times a day for 10-15 minutes on each session.A good lower back stretch that i still do is,lay flat on back and bring each one of your knees to your chest one at a time and hold it there for 10 seconds.Do about 5 of them on each leg.It'll give your lower back a good stretch.Try and keep yourself active in each day as well.What i mean is,do some light work e.g,30minute walk,swimming even a bit of cycling to keep the weight off.GOOD LUCK and GET WELL SOON