Your DS sounds exactly like my DD3. From my limited experience of 3 girls, DD1 started sleeping longer at 16 mths, DD2 started sleeping at 2.5 yrs (EXCEPTIONALLY BAD SLEEPER - 5 times a night from 6 months to 2.5 yrs...but that's another story) and DD3 is behaving just like your DS.

I understand how you feel. My approach is that it will improve in time. I know it will. What helped with me was when my DD1 was around 15 mths, DH started putting her to bed. I brought forward the BF to 6.45pm and then DH would settle her to sleep in her room. Initially in the rocking chair, then in the cot with his hand on her & a soft song. He did this for a week and then i did the same approach if i was putting her to bed. I still fed her in the night if needed but it quickly became just the occasional feed. I think it was probably a coincidence but DH being able to settle her and her sleep improving did happen at the same time. She was just ready i think.

Sorry, i've rambled. No real advice other than i know it will improve in time. Good luck!