DS hated tummy time. he had no proble holding his head up, he just hated it. the only way he would do so happily was if he was skin to skin with DH or myself, so thats what we did.
But you say he doesnt like that anymore..
What does your mchn have to say? oirs suggested even just leaving him on his tummy for a few second was OK if we did it a few times a day.

One hting I was told to do, this was somehow b/f related, was to put him on his tummy, arms by his sides, and get him to move his arms forward on his own. he hated it, so at first id not leave him for more than a few seconds, but he did get the hang of it eventually.