I just joined this forum so maybe you found a way since your post.

There's a technique called theta healing which can be used to change beliefs. I can't post links yet because I'm new to the forum but there is a company called Bourgeon that teaches it and they have some free videos on their website. You can teach yourself anyway...I used it once to heal recurring ear infections! There is probably a lot of examples on youtube as well.

Otherwise self-hypnosis and meditation are good. There is also a guy, Dr Joe Dispenza, he has some meditations on his website that I started doing to help with my mindset about my specific person. I haven't done it regularly enough but I believe it works and he really knows what he's talking about and he's all about changing beliefs.

All the best, I hope it works out for you!