僕 means “I” only used by men. It’s less formal than 私 but more formal than 俺.
を indicates the direct object of the following verb.
喰おうとした is the past tense of 喰おうとする. A verb volitional form followed by とする means “to try to do something”. 喰おう is the volitional form of 喰う which is the rough way to say 喰べる meaning “to eat“. So 僕を喰おうとした means “you tried to eat me”.
There is the other kanji for eating (食) which is more commonly used. When it’s combined with the kanji, “口” meaning “a mouth”, it means “to eat in order to live or survive” so it’s often used for animals. It’s also used for ghouls as they eat in order to live rather than for fun.
んだ is the broken version of のだ which is used when giving an explanation about the context. So he’s explaining the good reason for what he’s going to do. So 僕を喰おうとしたんだ means “you tried to eat me“ in an explanatory tone.
僕に喰われても means “even if you get eaten by me”. “A verb te-form followed by も” means “Even if one does something”. 喰われて is the te-form of 喰われる which is the passive form of 喰う so 喰われても means “even if you get eaten” and 僕に means “by me”.
仕方ない literally means “there is no way to do something” and it’s often translated as “it can’t be helped”. It’s mainly used when an unpleasant situation cannot be avoided and must be accepted.
Lastly, よね is the sentence ending particles meaning “right?” used when you want confirmation from the listener.