Netanyahu is no doubt an evil bastard. As for Israel's future that's much harder to judge. Israel currently has and will continue to enjoy US's full political and military support for obvious strategic reasons (control of oil & petrol dollar). Arabs are not really united against Israel. Many gulf monarchies are content with Israel as long as they get to keep their power and continue to get rich.
I also don't see any large shift of support away from Israel in US domestic politics. On the left, only progressive democrats are openly against Israel but old guards and moderate democrats are not going to let them take control (remember Bernie sanders). On the right, Isolationist MAGAs are not so much as against Israel as they are against costly foreign interventions. In the event of Vance taking over, US would still provide Israel with logistical and intel support giving IAF a decisive advantage.
Israel is also not sitting idle when it comes to countering negative public opinion in US, The forced sale of TikTok shows Israel understands the power of social media and actively wants influence younger generations.