How do I get nausea and hunger potions?

Mods are not needed to do this. You can get all these potions and more with commands.

For a swiftness potion:

/give <player> minecraft:potion 1 0 {Potion:"minecraft:swiftness"} 

For a hunger potion:

/give <player> minecraft:potion 1 0 {Potion:"minecraft:hunger"} 

For a nausea potion:

/give <player> minecraft:potion 1 0 {Potion:"minecraft:nausea"}

If you want the effect to be amplified (e.g. Strength 4 or Speed 18 etc), you could use this:

/give @p potion 1 0 {CustomPotionEffects:[{Id:(id of the potion),Duration:(number of ticks it should last),Amplifier:(amplifier value)}]}

If you want more than one effect, this also works:

/give @p potion 1 0 {CustomPotionEffects:[{Id:#,Duration:#of ticks,Amplifier:#},{Id:#,Duration:#of ticks,Amplifier:#},{Id:#,Duration:#of ticks,Amplifier:#},{...}]}

If the amplifier is negative, it will do the opposite effect. For example, an amplifier value of -2 on a health potion will reduce your maximum health. On a Strength potion, it will reduce the amount of damage you deal.

You can just do this command to get nausea potion, and just do the same for hunger but change the 9 to 15.

/give @a potion 1 8256 {CustomPotionEffects:[{Id:9,Amplifier:10,Duration:600}]}