I'm so sorry for your loss, I hope you get a sticky BFP really soon. I will say though that sperm morph or speed does not play a part in miscarriage, I have asked this to several RE's, they said that no matter what shape the sperm or how its moving, inside its genetically the same as a normal shape, normal moving sperm...plus a poor morphology sperm cannot penetrate an egg, a perfectly normal shaped sperm can only penetrate the egg. I was told that the only thing that could cause miscarriage due to the man is if he carries chromosomal abnormalties in his sperm, which is completely separate from his shape and speed of sperm, sometimes chromosomal abnormalities can be the cause of the poor morphology though, but poor morphology itself cannot cause miscarriage.
Once again, I am so sorry, I can't imagine how hard it is to be trying for so long and experience a loss, I so worry about this with myself if it ever happened, I don't know how I'd handle it