HM, it is unfortunate that you had two birds die without having a necropsy done to determine why. And it's equally unfortunate that you ignored your little friend for so long. But, you now have a chance to rectify your past mistakes with him ~~ and that's wonderful.
Of course, your bird is afraid of you. He/she has reverted back to a wild state, which is to be expected. Our companion birds are not so far removed from their wild ancestors that they won't revert when excluded from the only flock that they might belong to ~~ namely their human family.
Before beginning to work with your bird, I would suggest that you look careful at how you are keeping the little budgie. Does he have a nice, large cage with interesting toys to play with? Is the cage in a place where he can watch the family but not be in the middle of a lot of activity? Is the cage, water, and food cleaned daily? Does he get 10-12 hours of uninterrupted sleep in a quiet spot during the night? Is he getting a good, balanced diet? Has he had a thorough vet check in the past few months? Once you have analyzed whether you are doing all that is physically possible to ensure his health and welfare, then you can begin working with your bird again to earn his trust.
I would strongly urge you to get a copy of Mattie Sue Athan's little book Guide to a Well Behaved Parrot. Read it from cover to cover and use the techniques to retame your friend. In the meantime, take him to your avian vet for a wing trim, and then sit near your bird's cage for 15 minutes or so a couple of times each day. Quietly talk to him. Read to him. Sing to him. Let him know that you enjoy your time together. He will probably calm down, slowly but surely. Just don't stick your hand in the cage nor leave the door open for him to come out on his own. Either action will mean that you will be risking him having to escape from you and that can lead to injury. Flying around the house at will is a leading cause of death in such small birds.
Once you've read the book that I mentioned, I think you will have some new and successful approaches to bonding with and taming your bird. Let us know how this progresses, please.