You can sleep train minus the crying. Put him in his cot, when he cries pick him up and soothe him and repeat the cycle. It’s so hard but I promise you, he’ll catch on. One or two nights of 0 sleep will get you a decent night sleep in the long run!!
We did the furber method at 6 months but shortened the times to a length we were comfortable with. You just do a bit longer each night basically. She did scream, but it really only lasted a couple of nights! She then went to waking only once at night but was like your boy. We’ve got a regression though and it’s tough 😭