Children seeing their dad

It physically pains me for my children to see their dad as he doesn’t deserve to be in their previous lives. And they deserve better, and that includes without him! He uses drugs (seeing them supervised) but I have a headache already just from stressin and the pains in my chest are something I’ve not felt before. I feel so angry towards him for his choices when he’s been given chance after chance (yes ik I’m a mug🙃) but I tried my hardest to hold this family together supported him through prison and his rehab when he came out and probation everything. It annoys me as I feel like they have failed me saying they’ll support me and they’re doing drug tests that are coming back negative when he’s admitted to using drugs and I’ve sent pics of proof ! I just can’t wrap my head around it but it upsets me so much when my LB is saying ‘where daddy’. He’s destroyed this family he doesn’t deserve anything 😡😭