I've been on tactupump for 5 days now and am experiencing the worst breakout. i read that this usually happens at the 3/4 week mark not within days?

See a dermatologist: Adapalene/ benzoyl peroxide used for mild acne for years. If more severe we use oral therapy. Both ingredients can be drying and irritating. Users need to be carefully instructed about how to use it and what to expect. Clearly you will benefit from a discussion with a DR who is experienced with it. Clearly you have not yet had the benefit.