I'm sorry you're so sad and having such a very hard time
I promise, you won' t always feel this way and better days are ahead. (((Hugs)))
I'd like to second the suggestion of seeing a therapist and/or psychiatrist and/or physician. You are describing classic symptoms of depression and might be helped by a short term treatment of anti-depressants. Talk therapy would be so good for you -- sounds like your self-esteem has taken a pretty good beating lately. Have you ever seen a psychotherapist before? They've helped me 4 or 5 times in the past getting through some really tough times.