This post is over a month old so I am assuming you have finished this game and moved on. Still, her is some advice from me.
The Hive is all about numbers and nothing about being efficient. When playing the Hive, your bases should be no more than 3 tiles apart. Overlapping is your friend. This will allow you to have more cities, build more units, and crush anyone who dares come in your boarders. On higher difficulty levels, this is more important.
I could not tell your social engineering choices, but I hope that as the Hive you went Police State/Planned. If you did, do not use Knowledge either (since you will not get the efficiency bonus). I go with power, but that could be just me.
Like with the believers, do not bother upgrading units. Just build the better ones and use old units to A) garrison (captured) cities B) swarm the enemy with. As a Police state, you can use 3(?) units as police. While extremely useful (while on the warpath) this gets expensive. Leaving the outdated units behind (do not forget the change tithe support city) will save time and effort. Also, 10 obsolete units can kill 2 fully upgraded units AND lower your support.
Removing fungus is overrated. Plant forest and remove rocky areas and let natural forest growth get rid of the forest for you. Unless you need more spaces for citizens to work OR you need to clear a spot for a new city, do not bother removing the fungus. Forrest are your friend.
This will not help on your current level (might hurt though), but use forest to control your population. When you get 1 or 2 non-droned citizens, growth can be bad. A forest ca help maintain your city’s population while you get the police units/recreation buildings to handle a higher population. As the Hive, you do not have that much energy to put into controlling drones.