Try practicing everything very soft for 3 or 4 days. Start with soft long tones up to only G or A above the staff using as little pressure as possible, rest, then play some lip slurring exercises also soft with no pressure,rest,then the first page of Clarke's technical studies ,also soft,rest,then the first page of Clarke's 2nd study with the etude also soft all with no or very little pressure. Put the horn away for the day. Performing every day doesn't harm your chops,but improper breathing and excessive pressure will. Think of this as form of physical therapy for your lips. If you do use any pressure put it on your bottom lip,not your top lip. Remember correct playing is isn't the enemy,but incorrect playing is.