looking for these mangas that I can't seem to remember.

1.possesive mother and her wimpy kid.
In this manga the mother of the mc( a little boy) pushes his nephew or cousin from a cliff, the cousin doesn't die but is probably a vegetable for life. I don't know why she did it. Both the boy and the mother kept kept quiet about it. Also the boy gets a love letter from a girl and when the mom finds out they (together) tear it apart.(guess she loves him?)

Found: Chi no Wadachi (thanks to @m_masato)

2.manga about a cold teacher
He gets assigned to some class (probably troublesome kids) he doesnt mix work with private and thus leaves as soon as his work hours end. I think there was a rumor that he killed someone. He has cold eyes(like a killer) and probably glasses, for the rest looks like a levi from attack on titan

Found: 1-nen A-gumi no Monster (thanks to @Sudo Kaname)

3.Giant ant villain
All I remember about this one is being in a hospital then getting transported to some other dimension. Group of people they have to find the ant lion I think. Someone transforms into a giant ant and goes after the group (probably villain) Ant gets killed by falling debris as he dug too much holes in the walls and caused the place to collapse.

Don't really know about 1 or 3 (1 sounds interesting tho) but 2 is 1-nen A-gumi no Monster

Sieg Heil

Number 1 is Chi no Wadachi

Number 3 is Chong Sheng - Resurrection maybe ?

Quote from Sudo Kaname

Don't really know about 1 or 3 (1 sounds interesting tho) but 2 is 1-nen A-gumi no Monster

Thanks, I really thought this one would be unfindable as to how little I remembered of it. Also thanks to @m_masato We now know that Number 1 is Chi no Wadachi

Quote from m_masato

Number 1 is Chi no Wadachi

Number 3 is Chong Sheng - Resurrection maybe ?

Number 3 is not it. It was definitely a japanese manga and it didn't have that many chapters

Number 1 is correct and I was really looking forward to reading it thanks

3.Giant ant villain
All I remember about this one is being in a hospital then getting transported to some other dimension. Group of people they have to find the ant lion I think. Someone transforms into a giant ant and goes after the group (probably villain) Ant gets killed by falling debris as he dug too much holes in the walls and caused the place to collapse.

The name of the manga was Hito Kui

Be kind or get banned