As for the OP's situation, I am most sorry that you must endure this. To not be valued is one of the worst experiences we can endure.

As said above, I would start to pull back on all that you are doing. Yes, it is very difficult to say 'no' or stand by and watch things not get done; but, in the long run, it should result in you at least finding value in yourself rather than seeking from others. You deserve to treat yourself fairly as it seems those around you aren't doing the same.