I am so sorry your so depressed, but sweetie you are a unique and wonderful individual and continuing to feel like your worthless without him is just not true.
He moved on and you are stuck in a time warp. I have been in a time warp twice for other reasons but I finally decided that life is to short and way to good to remain stuck.
Instead of focusing on doom, stay in the moment. Give yourself breathing space. Consider what matters to you. Establish a few manageable goals, then take small steps toward achieving them.
Depression can be like a tremendous weight, keeping you down so you don't want to function. Sometimes, it's a constant battle with oneself to get up, get ready and get dressed every day. Life has a way of piling stuff on us, and it is our job to un-freeze our bodies and keep going during even the most difficult of times. Don't give up on yourself for having depression, it is possible to increase your energy and drive. It just takes finding out what solutions work best for you specifically.
I am just excited that you go out and go to the library............that is a huge step as many people cannot get out of their houses.
Do not let your ex define who you are, so he is gone and that has really crushed you but let's get out the super glue and make your stronger and learn to love youself.
We are here and we care, so let the pain in and then let it back out again. Stay in the moment. You cannot change yesterday and tommorow will be here soon enough so stay in the moment of today.
Feel the sun on your face and accept that you are a wonderful person.