mentality of being down when you are up

[SuperSnort]

hi, first post in this forum.

whenever i make money in a day, say that i had 100 at beginning and make that up to 500 by afternoon, and then later on in the day lose say 250 and move back down to 250, i feel like i am down and this sometimes makes me tilt, cause i feel like i have lost loads, even though i am up for the day.

how does everyone else cope with this, and how do they decide the period from which they will decide if they are up or down in
ie i always try and base if i am up or down in days, not sessions

any help also in ways of stopping oneself from tilting would be appreciated and ways you find best to cool off from beats or heavy losses

thx in advance