The past three days were definitely an improvement but I know it could be temporary. Everyone is different so don't be concerned if you don't feel any better for a while. I could plunge back into despair in a few months whereas you may feel more optimistic by then.
What I do believe very strongly is that, if you keep working your way through the grief, accepting the pain and all the other feelings, but remaining determined to build a future for yourself, you will eventually succeed. It's the timescale that can't be predicted.
We each have different life experiences, different resources of strength, different amounts of support, and there are differences in the manner in which we were bereaved and the things that happen to us subsequently. Each journey is unique but if we keep travelling we'll each discover a new landscape ahead. You can give in to the pain when it hits but you must never give up.