offensive language

I don't get offended too easy but i guess you could say that I have offended others with some of things i have said. I use to use the word gay alot like almost for anything i didn't like. For example i'd say this homework is gay or aw man its raining that's gay or something of that sort. Anyway though i had just met a guy at my first job and i was training him and he was telling me about a situation with him losing a previous job and i was just like aw man that's gay. And before i knew it i was in my bosses office and he was getting on me about using offensive language at work. Turned out the guy i was training was gay needless to say i felt pretty bad.