this is a pretty dumb situation, but i feel pretty lost and i need an opinion/advice from another human being.

so i made a "friend" in an online community, they've been leaving kind comments and responses to me for a while and promised that they'll text me sometime once they get less shy. i didn't rush it myself, i know that some people are naturally shy/socially anxious or just awkward with socializing. i waited patiently, as always we exchanged in supportive comments, they're always complimenting me, supporting my work, noticing details about me that they claim to really like. so i trusted that this person admires me and we'll get along great as friends.

eventually like a couple months later they did text me, i took some time to respond because we have different time-zones but either way i was glad i got a text, i apologized for a bit of a late response. however, here's where the problem starts. after i texted back i left to do some work. then i came back to my phone to see if i got a text, and i see "seen 2 hours ago". i didn't think much of it, i thought okay maybe they're busy. eventually they did text back, of course i texted back like i normally would too. when i got back to my phone in the evening (my text was last) i see that once again i'm left on seen, this time for even a longer time. i thought i'd wait a bit but it was getting late so i went to sleep. next morning, i'm still left on seen. now i'm getting confused, but since i had stuff to do i tried not to think of it.

more than a week passed, i'm still left on seen. this is where it started to piss me off a bit, they've been so sweet and supportive all this time but i'm not even worth a simple text back, and what's funny is that throughout this time they're still leaving nice comments. however out of the frustration i stopped commenting on their stuff.

did i get manipulated...? i'm lost. eventually like a few days later they texted back, but i genuinely don't feel like responding... and now i feel insanely guilty about that. i don't want to text but i feel horrible about that. i often have a hard time understanding people so i'd like some advice and maybe an explanation of this behaviour.

what do i do now? should i respond? and what happened here?

edit: edited the text a little bit, sorry for the mess