Erica, it really seems that you are sufferring. I'm so sorry about your cat. Thats such a difficult thing to do.
Don't try to conquer this alone. Get some help. If you have insurance, go see a psychiatrist and get on some depression meds. If you can't afford that option, look for free counceling. Churches sometimes have volunteer councelors who will see you for free. Find a depression support group. You should not be alone when you are feeling this way. All that sleeping you are doing is a major symptom of depression. Are you having any suicidal thoughts? Even if you really would never consider suicide, you may be having suicidal ideations and those are another sign that you need help getting out of the depression. You shouldn't have to live like this when there is help available. All you have to do is ask for it. You are not a loser. You have lots of company. Depression is a disease just like any other.
If you were diabetic, would you deny yourself insulin? Surely not. So don't deny yourself help for the depression. You are entitled to it and deserve it.
The boyfriend obviously doesn't have a clue. Don't rely on him for support, it doesn't sound like he's got it in him. Take the bull by the horns and do what you need to do.