I had an uncle like you, Somebody, no one is a 'Nobody'.
He had an financial insecure (in the 1930s in Yorkshire) and loveless (his mother never wanted him, and made that clear) childhood. He got a good secure job in the civil service and did very well, Yet like the OP he never felt secure financially.
He too would have given himself a GN name like 'Nobody'. His irrational fear of being penniless, despite being well-off was routed in his deep conviction, as a result of his childhood, of being a worthless human being who deserved nothing from life and as a result,that when life went well, he was always convinced that, as he didn't deserve it, sooner or later he would get his just desserts and everything would be taken from him, or just disappear.
Somebody Like others on this thread, I will deal in some amateur psychology, and suggest that your problem lies away from your financial security and in your experiences of life, probably, in childhood. You may know what that was, but perhaps need to talk it through with a councillor to understand how and why it affected you so deepley.
As a first step forward, change your GN name to one that acknowledges you for what you are - Somebody, who is important to your family, the outside world, and the community on Gransnet.