the orthodontist should tell me something before this happened

I thought the orthodontic treatment will be completed without much inconvenience, but in fact it is not so simple, I realized it after three of my teeth being extracted,now I am not able to speak very clearly and I can only drink milk,fruit juices ,eat pumpkin mud, and I have other symptoms of infection or fever. if the orthodontist had told me what will happen ,maybe I can prepare for this situation earlier, but she just told me not to eat sticky and hard foods ,and not eat beef which may end up with residue stuck in gaps between my teeth.
maybe it is my fault, maybe the rest of my teeth do not work as well as the dentist anticipated, they are really ugly, crooked.