Are you in therapy or have a mental health professional you see? If not and funding is an issue, have you reached out to local free/discounted healthcare groups to see if there’s mental health resources you can get access to? Unfortunately on the internet like this, we aren’t professionals and can’t provide that kind of help.
They’re certainly less touchable because they mostly exist outside of normal spaces - private drivers, private planes, curating who’s at events, etc. They’re not untouchable so much as it’s too much annoyance/effort to deal with them. I mean, hell, the very idea of a hired assassin is basically entirely made up by Hollywood. The military assassinates people all the time during war and coups on foreign soil (albeit a lot less than they used to) and civil disrupt in the homeland, but that’s because they have the backing of a government to protect them. There are some rare targeted instances of sabotage (Havana syndrome may be a modern version of that) but those are also suspected to be tied to government. Any overt assassinations in another first world country, even if backed by a strong military, would likely be considered tantamount to a declaration of war, and I cannot imagine a situation in which it would not be difficult to figure out that another country was behind it.