You tried to toilet train her in January? That’s your problem then. Were you not aware that you’re supposed to start toilet-training around 2yrs old? If you leave it too long, it can become harder as they get entrenched in their ways, know their own minds, and can be quite resistant.
I’d start with the nappies and be quite firm about it. She’s not 18 months old, she’s 4 and starting school in a few months. She’s old enough to understand. Let her choose some nice pants, get two potties minimum, a toilet seat insert depending on her size - and do not use those pull-ups that just make it harder. If you can get some towelling pants, they’re ideal as they can feel the wet against them. Use a Star Chart and promise a reward at the end if she achieves, eg a toy she wants or a special trip out.
The bottle, again, should have stopped ages ago. Once they can drink out of a sippy cup, you swap to that for evening milk, then a normal glass or beaker. I’d leave the bottle while you sort the nappies, but then stop it by changing it for a pretty cup and moving it earlier in the evening so she can brush her teeth after.
The expectations of school are higher than you must realise. We don’t expect to be dealing with babies, and children who haven’t been helped to the right levels of maturity by their parent(s) stand out. I feel very sorry for them as school can be a massive shock. It’s not their fault and they don’t understand why they’re suddenly being expected to do things.
Work hard getting your daughter ready. Praise her, give her extra responsibility eg fetching things for you, drying her own cup, etc etc, all the while telling her what a big girl she is and how you’re so proud of her.