Toddler just wants to lay on floor all day

I need some help. I see other posts with parents saying their kids do not like toys but then follow up with, they like puzzles and swing chair and going for walks etc. My 2.5 year old doesn't like any of that. She just lays around all day.

She won't do books, toys, dancing, nothing. She likes tablet time and when I flip her and toss her into cushions. That's the only way I can teach her anything. (Like look at mommy and we will flip. Or show me the sign for again and we will flip.) It's getting old though.

She is very unbalanced in walking and she will not crawl. (PT says she has a poorly developed vestibular system). So she walks for like 5 to 6 steps and sits down. She is unbalanced on grass and mulch so she doesn't like walking outside.

I put her in a chair and she just goes full 'rag doll' unless it's her highchair. She is non-verbal lvl 2. She points and nods yes or shakes head no and babbles but that's as far as she will communicate. When I show her stuff, she looks away like she is uninterested in stuff. I can't teach her anything or play with her and it's like I'm talking to myself all day. I've read so many books and nothing is working. She lays down every single chance she gets.

I'm losing my mind. Some days I just want to leave the tablet on so everyone is happy. (I haven't given up hope yet. It hasn't gotten to that)

I don't want to send her away aba, they want minimum 30 hours a week and that doesn't include her 2 hour nap during the day. I wouldn't see her all day 😞. They don't have at home aba for where I live because I'm more than 15 miles from the nearest center. I'm a SAHM, I can give her 100% of my attention all day. I should be able to help her.

Can someone tell me anything. Even 'it gets better' would help. I don't see a light at the end of the tunnel right now and I feel so... Stuck. Does anyone have similar experiences with their kids at this age?