illusion

Idea is a word that is spelled the same in English and it is in Spanish.
This is my dilemma of dilemmas: "no sé si seguir haciéndome, o qué".
How do you translate this? "I don't know if I can continue self-deceiving myself or... what?"
My first question is if I should continue to write in English or just let it be, and write just in Spanish. I believe that, although Ideas are universal and "all that stuff", they have their dwelling in language and also take different meanings in different languages. For Example, the word Illusion in English and Ilusión in Spanish, have very different meanings. Juilás Marías wrote (among other things) in his Breve Tratado Sobre la Ilusión (Brief treaty on Illusion) about the huge difference of Ilusión and its sense in Spanish, comparing it with the original meaning in Latin as in other languages. (illusion in English means false idea, deceit, mistake in perception and has a negative sense). However, as Marías says, "in Spanish, from a moment which will be necessary to specify, appears a sense that is fundamentally different, positive, valuable, that reaches the highest appreciation". This positive meaning is the same as "having hopes and looking froward for something and somebody with enthusiasm" «con ilusión» and something else; One thing is be in the illusion (self-deceived) and other is to be full of illusion (of dreams and expectations, but with something else: excitement, hopeful future, a feeling that cannot extinguish itself after the fulfillment of the dream, but endures even further, because to be in illusion is not the same as living illusion(ed) as an adjective.
This is my second question:
"No es lo mismo ser que estar" "it is not the same to be (Being as an essence) than to be (being as a circumstance)" as Alejandro Sanz would sing. Indeed, it's not the same! For that same reason, what I think in Spanish and can't say in English, is as much as I learned in English and (at least try to) translate into Spanish.