Congrats on making it to level 8, I’m in the same boat 
A lot of the recommendations that @mindjockey made I totally agree with.
Japanese Ammo with Misa is pretty good at explaining grammar and sentence structure but I do also watch Japanese Pod 101 YT videos from time to time. I just found a pretty good Basic Japanese Grammar video of theirs that explains Japanese particles which I still am trying to fully understand.
I also use Tae Kim’s A Guide to Japanese grammar as a supplementary resource when I need further explanation.
For speaking, I use Pimsleur doing 1 lesson a day. It’s very basic words/phrases at the beginning and builds on that making more detailed sentences. It does have the SRS technique as well asking you say a phrase you learned many lessons ago.
Good luck!