Struggling with toddler and baby

I'm a SAHM with a 2.5 year old girl and 3 months old baby. I hate to admit but I can't take it some days, it's starting to take a real toll on my mental health these days. My toddler doesn't listen, doesn't help to tidy up, refuses to eat unless sometimes if I feed her (I don't want to!!) and strops a lot. I know it was a big change to have a sibling but I'm always trying to accommodate her, prioritise over the little one. I'm exhausted. Don't know what to do. Don't have money to send her to nursery, one set of grandparents are abroad, the other ones help every few weeks if we ask for help but not offering it so we don't really like to ask (my husband's parents.