I second what everyone else has said.....give it time. On one hand, you have a very playful "baby" who is wanting lots of play time and attention. On the other, you have one who's been with you for a year as your "only child" so he's "set in his ways". You've introduced someone to HIS turf and he's upset. But it WILL get better
We have had Gabby for 8 1/2 years and recently rescued Gage, who is a year old. He still has lots of "play" in him while she's so set in her ways, it's crazy! She growled at him alot when he first got here but I showered her with lots of love and kisses, kept telling her she was a beautiful girl and momma's baby. She's finally gotten to the toleration stage with Gage so things are definitly improving in our house
So rest assured that things will get better.