Autistic brother selling insurance

How would you handle this ongoing repetitive situation? How do I lovingly stand my ground without hurting him?

My amazing loving brother who happens to be autistic, has been selling (trying at least) insurance from a company for the last year. He’s maybe made one sell in the year and blames everyone for not giving him a chance. I’m not in the least bit interested about switching to the company due to high rates and it being a pyramid company. Over the last year dear brother has asked at least once a week to crunch numbers or to “bring me on to sell with him”. I’ve explained to him we just aren’t interested and I can’t make the switch to work for him because I already put so much effort and hours into my current business I run. But every week it seems I break his heart all over again by telling him no or that I can’t or won’t help him. I feel absolutely horrible to break his heart all the time but still am not comfortable switching everything to this company. How would you handle this? I feel like a horrible sister for not “supporting” him. I do try to offer suggestions on jobs that he would have more success at but he is insistent that he can make the big bucks with this company if people just give him the time. Ugh please tell me I’m not heartless. 😩