As yung_lean said, '자나' is a misspelling of '잖아,' which is the verb suffix for something that the listener already knows. Adding '도' to the verb gives it the meaning of 'even though (verb).' V + '고싶다' means 'want to V.' '못' is a particle which changes the sentence to mean that you are unable to do the verb. '보다' is the verb meaning 'to see' and is used in both clauses of the sentence. The sentence is literally 'Even though (I) want to see (you), as you know (I) can't see (you)." A better, more natural translation would be "I miss you, but I can't see you."

I believe 못보자나 is a common misspelling of "못보잖아" and if that's the case then I think they're saying "I miss you too, [but you already know] we can't see each other" or "I miss you too [but you already know] that I can't see you." Something along those lines. to break it down: "보고싶어" --> "I miss you" (literal translation "want to see") "~도" is an additive particle meaning "also" or "too" or used to emphasize the preceding word "못" is a negative particle, "~잖아" when added to a word indicates that the speaker & listener both already know something so "못보잖아" is a combination of "못" (negative particle) + "보다" (to see) + "잖아" (as you already know). not a native speaker, perhaps someone will correct what I've said:)

-자나 is a very informal way of spelling -잖아.