xp orbs follow you and you can not pick them up

I made a mob farm and after going AFK half of the XP I made was gone to waste because I could not pick it up. and it would just follow me endlessly until I ran or if I dropped down 10 or so blocks. and if you get lots of orbs following you it can get very laggy.

the result I would like to see
1. XP does not follow you endlessly
2. XP creates less lag

The Gaming Rainbow