Should a marriage proposal have conditions?

My fiance, if i can say that anymore, proposed to me in March of this year (2011). This has been after about 10+ years together (on and off). The other day we had a stupid and I mean petty fight. This somehow blew up into something huge. This happens sometimes with us, bringing up either bottled, past and present issues which has nothing to do with the current fight. Well...within the heat of the fight he tells me he no longer wants to marry me. This, apparently, is due to the fact that I have an "attitude" that needs changing....we have since somewhat recovered from that particular fight, but never revisited the issues surrounding the argument that caused us to not talk for days. Today, however, it started small and the unvisited issues that we were previously fighting about came up again. He tells me that again, I have an attitude that he doesn't like the so-called attitude comes out in the midst of a fight...(It's not ALL the time as he makes it out to be). He says I better change it or I will never get my ring back. What kind of stuff is that? This is why I ask, should love/marriage proposal/marriage have conditions?? I asked him, why did you ask me to marry you in the first place? To which he replied, "because I love you." I then tell him, NOTHING has changed about me from the day you decided to ask me (after all these years), up until now! So how can you take the ring/proposal away because of a simple thing you don't like about me?? What is different today than two months ago? Nothing! I am typically a warm-hearted, thoughful, caring, loving person and mother of his children. Do I get angry/frustrated/upset sometimes??? Hell yes! But it's not who I am! That's not what I'm made of! Now, is that a reason not to marry someone???