Perhaps what inspires you is different now - the old things that used to inspire you don't seem as important anymore? - or that you've satisfied your curiousity with those things perhaps? Perhaps the block is the mind's way of relaxing.

Interestingly someone once described the coming and going of feelings like the tide coming+going - it's going to happen anyway, and they won't really harm you, so let it come + go by itself - the sea in the tide has no way of turning, you cannot override how you feel indefinitely through willpower, it only changes when either the situation and/or perspective changes. Anger and sadness happen, but they go naturally when that issue's dealt with, and if not by change, it has to be by acceptance - if you accept the refocussing of your skills and interests, you won't be frustrated

As you know, you don't have to have an exciting, or even happy, personal future to make your life meen something to those you can help - if feelings are the only thing cabable of giving anything meaning (in terms of feelings), then you can make your life meen something that way - you have experience of depression, that would make you experienced and understanding enough to become a counsellor/samaritan - perhaps as a volenteer to practically let you walk straight into the post - society is well in need of decent concelling, and you'll be there when people need you the most. Using the experience would make something good come out of what you've gone through, you could help people realise what would free them so they don't have to face what you did to realise the same thing, and it would give you meaning + self esteem