How do you deal with feeling dead inside?

I think you are at the beggining of a wonderful adventure. realizing nothing has any intrinsic meaning means you have stepped out of consensus reality and the "meaning" you had been brainwashed with. secondly, existing in nothingness is actually the goal of many eastern philosophies because you are essentially awareness sitting in nothingness, that's where people go when they meditate. in emptiness lies the greatest peace of mind. the good news is that now you have complete freedom. you can decide for yourself what meaning you want to give to your own existence. this comes with a great responsibility because once you've stepped out of illusion if you don't actively choose a meaning to give to life it will continue to have no meaning. this is what is meant by Jean Paul Sartre when he said that existence precedes essence. it means we were indoctrinated to believe that life has a secret meaning and we must find it, then religion came along and said that god is the meaning and you must obey and follow and pray and hope that you will be allowed in this sacred place where meaning comes from. but that was just that , indoctrination, really nobody knows what the meaning of this experience is and anyone who says different has just arbitrarily given a meaning to it. but since you are free, you can choose what meaning you want to give it. you can choose that your life will be about exploring this planet, you can choose that your life will be about heping others or you can collect stamps, you just have to decide.