Replying to Need legal advice

Today I was arrested for possession of 6 grams of marijuanna. But first I'll explain the story. So me and my friend were at a spot and he was smoking in a shack and I was outside the shack when the cops showed up. So they strait up went in and my friend completely admits to it so they check him and find weed (he consented to a search). Next they ask if they can check me I say I do not consent to any searches then to which they said we have the right to search you if we arrest you. so they arrested me for possession of marijuanna before even seeing any form of marijuanna in which after they forcibly search me finding 6 grams or marijuanna. So any ns who are experienced with Canadian (Ontario area if that helps) can you please give me some legal advice. What should I do was that illegal search and seizure?