Sleeping

My son won’t sleep in his own room own bed.

Me and his dad have split we split back in January, my son lives with me weekends he see his dad. My son won’t sleep at night Iv tried everything I could possibly think of, tried bottle at night, tv so he hears voices in background so he knows he not alone, night light, calpol, put him to bed earlier put him to bed later, taken him out to park to tire him out, nothing works, he wakes up between 5-7 times every single night. Apparently he sleeps fine with his dad wakes once or twice but I know he puts him in bed with him so they both get sleep which isn’t going to help me. Anyone going through or gone through similar situation? Any suggestions what I can do? Iv spoken to my health visitor and she has suggested waking my son up before he tends to wake up so I get him out of that sleep cycle well that hasn’t worked everytime I go wake him up he woken already. Please help 😩