Blowing and picking my nose after septoplasty, could I ruin my results?

Thank you for your question.  Most likely, you did not "ruin" your septoplasty but I recommend reaching out to your surgeon to discuss your post-operative concerns.  In the meantime, it is very helpful for patients with allergies to treat them with oral anti-histamines and nasal saline irrigations to cleanse the nasal airway, instead of blowing/picking.  Hope that helps, best of luck to you!