Were Patroclus and Achilles lovers

Yes. Achilles cherished Patroclus above anything else. His father, His child, everyone. In the Iliad it reads that even if his father or son had died it would not have grieved him the Patroclus' death grieved him. He tore out his hair and caressed Patroclus dead body for days on end crying and said his only mission in life from then on was to kill Hector and join Patroclus in the afterlife.

They fell in love when they were both young. They grew up together, they studied together under the Centaur Chiron, they went off to the Trojan War together. They loved each other when they were boys and they loved when they were men.