I have a question for you all...

When your kids started talking more, would they say a word then not use it several weeks after? Lily has been saying a lot of new words lately and will say them 4-5 times in a row then won't say them again or not til ages later. Like about a week ago she re-peated the word 'tiger' but hasn't said it since. Today she has been excellent. Her new words today were ball, bowl, belly, Teddy and she tried to say Lily, but only managed 'Lee'. I can pretty much guarantee she wont say them again for awhile. The only words she uses every day are mum, dad, bubby, yum, bye bye, ni ni(for goodnight), hello, hey and puppy. which is whole lot better than a couple of months ago. She also points to some body parts when i say them(hair,face,nose,foot,hand). She is growing up so fast. The only problem i do have with her is her extreme tantrums. Nothing is working. I wrote a post about it a week or so ago. Since then its become a nightmare. For instance, she hates being in her car seat. She can get out of the straps and they are as tight as they go. Well yesterday, we went out shopping. Came back to the car and put her in her seat. But she wouldnt let us strap her in. She went completely mental. hitting and screaming, we couldn't go near her. This went on for 30 minutes! Im just not sure what to do anymore. It can't continue, especially when bub comes along, which is very very soon (have an induction date for next week). Just feel really helpless about it..