Hi there...and firstly NO... You are not mentally "sick".. and please , never think that. You are perfectly normal in experiencing these things. " What goes around, comes around"...:you've heard of that?... In former lives you may well have been the mum... Whereas in this life you are the daughter
Those that have a close bond will come back in some form or another in different lifetimes, in one guise or another. The fact that you may recognise this , or are being shown this, is confirmation from the universe ... You are being blessed.