alcoholic ex

me and my ex we’re together for almost 3 years and we’ve recently broke up (to try and grow individually) we were gonna get back together but hes been lying to me about drinking for months (including while he’s driving) and he’s currently in rehab. (im 19 hes 21 btw) we had our whole future picked out and i for sure thought i was going to marry this man. idk what to do. pls help. i love him so much and he’s my best friend which is why its so hard to let go. i still want him in my life but i dont think i could date him again after him lying to me like that