my ex is stopping me from moving on

i was with my boyfriend for 1.5 years and for the last 6 months i began to have feelings for my new best friend who was a guy and it was clear he had feelings also. my boyfriend was so jealous of our relationship and always thought my best friend acted really weird with him and i began to hide our messages etc to avoid him getting angry. both my boyfriends friends and my friends both became suspicious about me and my best friend because we were clearly very close and my boyfriend began telling our friends how close we seemed and how my best friend seemed to be acting weird and many of our friends got angry at my best friend for disrespecting the fact that i still had a boyfriend.

about 2 weeks ago i broke up with him because felt like it was so wrong for me to be feeling the way i had been and staying with him. i felt sad when we broke up but straight away my feelings grew stronger for my best friend and it is clear we both want each other. i want to kiss my best friend and be with him but i still have a lot of love and respect for my ex and i know he would be shattered if he knew and i also don’t want all my friends turning against me if i do.

PLEASE i need your advice on whether i just do what i want and go for my best friend or whether i should respect my ex and choose being on good terms with him and my friends over that ?????

thank you