Editing is such a pain!

Now that I have some usable footage, I tried putting it together. I knew I had been using the old imovie software, s I decided to buy the latest on off the app store. There are many more features, however theres one big problem; the playback lags so much I can't edit properly! I've tried everything from cleaning my laptop out to restarting, but I guess my computer is too old to handle the software... This is very disappointing seeing that I had to pay for the latest imovie and I was going to rely on some of these features. It has become very annoying to try to edit, so I might just revert to the old imovie. In other news, as I sift through some of my footage, I realize I need smoother shots and more of them, so I scheduled to film tomorrow with my actress to see if maybe I can get all the footage I need. I am very lucky to have such a good friend as an actress because she is very willing to participate in the film, which is what is needed when on a deadline. I feel as though the thing I am going to struggle most with is sound, especially because my opening relies on the aspect of film so heavily. I need to record more sounds with the actress herself and just get the last shots. I still need the second part of the film, so I will also try to get this done tomorrow. Hopefully everything works out so that I do not have to call upon her again and I can just focus on editing and the looming critical reflection.