Baby fights sleep

Hi mummies, I'm a bit desperate and need some suggestions. My son is almost 13 months and still needs to be carried to sleep. I and my husband have to take turns to do this and it is really taking a toll on us - on our backs. Plus we need to stand while doing this (we are using baby carrier/sling) . I wouldn't mind it but the backache is getting worse and he is growing. Hence, I am worried how long this will continue and affect our back pain. On top of that, my son really cries and fight sleep even though he is so sleepy which makes it more difficult because we feel so guilty for even putting him to sleep. Night time especially after work and when we are all tired, is the most frustrating time to go through this. He only has 1 nap a day (noon) and he sleeps only after 10pm. I tried to make him fall asleep on his own on the bed pretending to be asleep, sitting down and rocking him on the sofa but it doesn't work at all. How and when can this pattern change? What should I do? Any suggestions please except for the crying out method because honestly I think that option is not for me, I don't think I can handle that. Even when he cries while im carrying him is making me feel bad, so crying out method will be a complete failure for me. Did anyone go through this and what did you do to change this. TIA.