Posture Advice Please

Hello, I’ve been dealing with cervicogenic headaches for a few years now and found out it’s due to neck tension/ poor posture. Went to a few pts and they said its tight chest/ weak upper back while on the other hand, 2 people said its an overextension issue. Me personally, I think it’s partially both but I think i may have a kyphosis of the upper back / poor mobility and other compensations are coming out from that root but I’ve been doing exercises with some result to none for each. Just hoping someone could notice something others haven’t yet, thank you.