Holding your hand. You aren't alone.
I had a miscarriage at the start of April and have a DD just turned 2. I had days of feeling flat and dull and sad even after the worst was over - but it's important to remember hormones are changing, it can give you huge swings in mood and energy levels.
It is natural and for me, it levelled out within a few days. I did still feel exhausted and run down for a good week after, though - taking it easy really is important, I was physically shattered afterwards and taking the time to rest really helped.
I have no idea how to handle the emotional side of things long term, myself, as I was able to accept rationally that this baby was not meant to be, but I struggle with accepting that DD might be an only child. I feel I owe it to her to keep trying, but DH is not keen to go through the trauma again so soon.
Going to the GP and having a good cry really helped, though - having someone say to me, it's ok to cry and it's important to grieve, was like someone giving me permission to cry and I felt much better after that. Up till then is been crying privately or feeling guilty if I showed I was upset in front of DD.
Hope this helps - there are so many good kind MNners on this board, it really did help me to be here.