Sorry I’m late to the party, but I did want to chime in on this topic. You’ve stated that your flashbacks are an important part of your plot and story, so I say go with it. There are different ways to incorporate flashbacks so that it’s not jolting but flows. You just have to figure out what works best for you. Also, if you’ve come up with this idea then I encourage you to trust your talents and instincts to be able to execute everything properly. If you’re unsure of exactly how to write the flashbacks then do a little research of how other people have done it and maybe one will work for you.
I used flashbacks in my novel and I had concerns with it to, mainly because I wasn’t sure how to do it without just italicizing each flashback. I Googled different ways of incorporating flashbacks and found really good resources, ways and explanations of other ways to do it. Hope this helps some. (Sorry for the ramble.)