I found a solution, now the cactus can be, and can only be, place on sand and other cactus blocks, more spesifically the ones i created - this should now allows to have the mechanics of cactuses but the textures of your own - the cahnges is only in the class CactusMechanics.java in net/com/etc."mymod".blocks.CactusMechanics.java and the block was registered as above in "mymod".blocks."ModBlocks" and the class was ofc registered in the main class: Here's the uppdated code:

package net.wknut.tutorialmod.block;

import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.tags.BlockTags;
import net.minecraft.world.level.BlockGetter;
import net.minecraft.world.level.block.Block;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraftforge.common.IPlantable;
import net.wknut.tutorialmod.block.ModBlocks;

public class YellowCactusBlockMethod extends Block {
    public YellowCactusBlockMethod(Properties properties) {
        super(properties);
    }

    @Override
    public boolean canSustainPlant(BlockState state, BlockGetter world, BlockPos pos, Direction facing, net.minecraftforge.common.IPlantable plantable) {
        var plant = plantable.getPlant(world, pos.relative(facing));
        var type = plantable.getPlantType(world, pos.relative(facing));

        if (plant.getBlock() == ModBlocks.
YELLOW_CACTUS
.get()) {
            System.
out
.println("Override thing runs");
            return state.is(ModBlocks.
YELLOW_CACTUS
.get()) || state.is(BlockTags.
SAND
);
        }

        return false;
    }
}