I need some help with a Card/Unit

Would be happy to provide some help, the crawling units you mention can either be the Nod Cyborg if it causes an electric shock effect when hitting a vehicle or it can be the GDI Zone Trooper which actually uses a railgun and has a big armored suit. Whether it is the GDI Zone Trooper or Nod Cyborg both units can be countered by GDI Rifleman/Nod Militants, GDI Wolverine, Nod Flame Troopers, and Nod Flame Tank.

The Hover tank which is the GDI Sandstorm is a late game anti vehicle and anti air, the best to deal with it are GDI Rocket Squads/Nod Laser Soldiers, your GDI Sandstorms can counter them if the get the first rocket barrage off in the case they are set up on the launch control platforms. If not then two squads of GDI Rocket or Nod Laser Soldiers will do wonders against them as GDI Sandstorms cannot do much damage to them while they take a lot of damage in return from those anti vehicle infantry. Do not send GDI Predator Tanks,  Nod Attack Bikes or Nod Scorpion Tanks against them as the GDI Sandstorm is very effective against these units and will kill them in one rocket barrage. Another unit that is a decent counter if you have it are GDI Titans (big walker mechs with a railgun) or Nod Cyborgs because they use an anti vehicle particle beam that slows down any vehicle along with their attacking speed.

When it comes to the Nod Rockworm, it currently is a problem as the only real good counter to is anti vehicle aircraft like the GDI Orca or Nod Banshee but again GDI Rocket Squads/Nod Laser Soldiers do decently well against it, along with GDI Zone Troopers or Nod Cyborgs. But do not send out GDI Sandstorms against the Rockworm as the Nod Rockworm is a heavy anti vehicle unit and will absolutely destroy anything that is a vehicle.

I hope my advice and suggestions helped, best of luck in your future battles.

You mean Nod Cyborgs (The Crawlers/Railgun)? They're infantry and are extremely strong right now because everything that is effective against them, they are also effective against. Your best option is using regular Infantry to go toe to toe with them (Flame troopers melt anything that is Infantry). Nod's Flame tank should melt them as well and be able to survive their damage as long as it doesn't get surrounded by them.

Sandstorm (Hover Tank/Shoots Missiles)? They're very fragile but dish out tons of damage extremely quick (To multiple tiles), however a bulky unit such as the GDI "Titan" or Nod "Rockworm" will absolutely smash it to pieces. Nod Cyborgs will also melt them.

Rockworms are a struggle to deal with for GDI unless you have the Orca, Nod's Banshee's can just follow and harass it as it surfaces. If you can't deal with it, just have your harvesters avoid it and have flying units to contest the missile if they use it to hold a spot. It has to be unborrowed for it to count as occupying the missile so a single flying unit can make it pretty useless outside of it chasing your harvesters/troops around. You won't see many of them but they're just too much of a hassle to kill, it's better to just play around it because it's way too damn tanky and escapes too easily.

I think you've gotten a lot of good advice here already but I'll add that one more small piece. One of the biggest things I see newer players fail to do in this game is to keep the pressure on their opponent. The rockworm is a very expensive unit behind the most expensive tech option, it is pretty much only an offensive unit, it has problems chasing things down and you can actually force it to surface where you want it to by microing ontop of its movement targets, it really is a risky thing to build if you're behind.

Most of the games I've seen where people are getting wrecked by rockworms its because they aren't pressing their advantage, they're sitting on the launch points watching as their opponent harvests tiberium freely to get a rockworm out and then support it with additional troops. If you control the map then go hit their harvester(s) or even their base, force them to respond to you rather than waiting and hoping that you'll be able to respond well to them. If I spend all my tiberium on a rockworm and you keep harassing my harvesters I'm probably going to have to use said rockworm to defend my harvesters, if they die one rockworm certainly isn't going to win me the game and the rockworm costs enough that I probably can't get out more than a handful of infantry for awhile after building it unless I'm already in the lead.

Thank you for all this, most of the balances you listed I still don't have, but I'm glad to know they are coming. And I'll try a few diff things to counter all those guys.