Some losses are greater than others. The loss of our childhood and early youth is huge. Hey, bitterness is merely repressed sadness and hurt. It's nothing to feel ashamed of - rather, recognize it has good cause, and then you can deal with it. It takes time and work.
Let those feelings out, in whatever way works for you (healthy ways). You might want to smash something, well okay, take a hammer to that old VCR that is sitting in the garage and doesn't work. You may have pent-up rage (I did). Maybe you like to pump iron, that is a natural high. Crying is a physical release of emotion - it's a good thing. Cry in the shower - it's private and feels womblike. Writing about how you feel is dealt with in a special way by our brains, and can be therapeutic, too.
:)
Mostly, know that your feelings are real, own them and know it's okay.
xo
tal