I've never heard of lordosis before, but I do know that people can have spinal problems either way, either too bendy or too straight. Lordosis sounds like it's a bit more bendy than just bad posture though.
Firstly I think you should get diagnosed by a professional because there is no use trying to sort out a problem you "think" you have, you need to know you definitely have it.
Then, they will probably send you to a physiotherapist, or if it is a bit more complex then perhaps operate.
Meanwhile, try yoga or pilates, if you don't want to go to a class, find a website or a book and try doing some of the positions for your back every day. Yoga is a long-term solution though so don't expect results pronto.