Flaky, dry scalp after lightening my hair, what can I do?

Hello! I recently lightened my hair from a very dark brown, to a much lighter, copper tone, in addition to highlights. I have always had a dry scalp, BUT, this is so much worse. My head is full of what feels like scabs. I just shampooed/ conditioned for the first time since getting it done (so it’s been 4 days). I brushed my hair, and there are flakes in it (UGH). What’s going on, and what can I do? I know some people swear by coconut oil. Would I put it through all of my hair, or just my scalp? Open to all suggestions!! TIA