First of all, take a deep breath! Your daughter will not starve! If she is on formula, she does not need cereal. My son was breastfed (never took to formula) and he hated cereal so we just went straight to purees. But what I'm saying is that she's already getting plenty of iron and vitamins from the formula so she really doesn't need the cereal. So if she doesn't like it, then don't bother with it. She might just not be ready for solids yet, or your timing might be off. This is what worked for us and you could give it a try and see if it works for you. When he would wake up in the morning he would nurse, so you would give a bottle, after like a diaper change and a couple of minutes of cuddling. Give her a bottle. About an hour after she wakes up you can try cereal, but don't get upset if she doesn't want it. You can also skip the cereal all together and try some pureed sweet potato or butternut squash or banana or prunes. If she doesn't want it, then don't worry about it. Then before her morning nap give her half a bottle and then another half bottle when she gets up after a change and a bit of cuddling.
For lunch, give half a bottle and then try pureed veggies. If she doesn't want the purees, then give the rest of the bottle.
Before he 2nd nap, give half the bottle and then the rest when she wakes up.
Same for dinner, give half the bottle, then try pureed veggies and fruits.
Another thing to keep in mind is that this might be upsetting her stomach and causing constipation and that's why she doesn't want it. To fix that, I used to give my son a couple of spoons of prunes with every meal and even now, at 20 months old, he gets prunes once a day.
Also, you have to be careful to wait like 3-5 days between introducing each new food to watch out for signs of allergies.
If after 2 days of trying this schedule she still doesn't want to eat, then give it a rest for 2 weeks and then try again.
Some kids just take longer to be ready. If at 8 months she's still not interested, then your doctor should run some tests and see if her digestive system is ok. She could also be teething and that's why she's not interested in eating. They are never interested in eating when teething.
Good luck!