lost contact with a friend.

So i made a great friend on TSR. We have been speaking for lets say over two months or more. More so Everyday. We didnt swap socials because i guess we liked the fact that we didnt know much about eachother and we just had to figure it out on here. It was a great friendship. speaking everyday.
Then i went on holiday, i said i would message when i got back. They told me to enjoy my trip and so on and said okay.
Its been over a week now and there is no response. I know this person wasn't that active on TSR but would still come to chat everyday but now they have completely dissapeared. I am pretty sure i told them that i was only going to be gone for a week (well i told them this a while back- not in the inital final message but still this person has great memory)
Anyways i am worried now. idk what to do. Maybe they just couldnt be asked to come on TSR again but the person didnt show any signs of not wanting to speak, they were always constantly messaging so yeah. It was a good healthy friendship.
Also i don't know the persons actual name. So i cant just search them up. I know what you're thinkinh. what kind of friendship was this....but trust me we liked to keep it suspicious and it was cool like that. we had other pet names we would call eachother. I am feeling so saddened...like i've lost something.
Any advice?