I love what Susan has written. You are not alone, the "wall" which you call it naturally comes after a long-trusting relationship and it takes a while before it disintegrates into nothingness and you can move on. I am also 25 and I think its our age to feel lost, confused, and perhaps scared because we are young adults, still need to define ourselves, and perhaps make a difference.
I think if you can focus on the betterment of yourself and tell yourself everyday that everything will be fine!
I thought I would share and let you know that you are not alone in feeling the weight of the "wall". I thought I had surpassed it but it took me being by myself to face the reality of my situation. But, this is just a beginning. One day we will look back at this and laugh! :)