Dog advice

Hi, I am the owners daughter of a 2 and a half yr old golden retriever, he’s a lazy chilled sometimes demanding dog.

He was snoring again, (he sleeps in my room) and I was moving him so he wouldn’t be snoring (head higher) usually he doesn’t care if I move him around a little or anything in fact he usually finds it like a game and does happy sneezes ect.

he has only bit me once when I was younger that time I was trying to pick him up and he randomly freaked out and went for me. I had done some looking into dog language (physical) since then.

this time when I tried to move him up a bit he started growling, I was really confused because usually he growls when he is playing but he was starting to do tounge flicks and I didn’t recognise his stiff posture too I was tired, and I kept on nagging him I was honestly wondering if he was gonna really bite me or if he was playing, he ended up jumping up and biting me growling and snarling I told him off (I know it’s wrong) and sent him out of my room and he bit me again. And before I say anything else I want to make clear I am completely aware i was in the wrong in this situation and yeah everything I did was wrong so please don’t harass me or tell me off I know I was wrong.

I am just curious now on what to do next how do I approach him will he hold it against me or be skiddish how do I apologise or gain his trust? I take care of him the most and I have been putting extra effort in to do so and I am now worried this set me back a whole lot. People who know dogs help pls.