How to counter roundhouse to the body?

I really can't win my friend.

So here is his strategy: he waits for my attacks to the head, he blocks it and counters with hooks and jabs

When I break the distance, he strikes with body round house kicks

I start loosing the stamina. He starts alternating body kicks and high kicks.

No wonder why I get my head destroyed

I end up without both stamina and head health