Hi Laila!
After reading your post, it sounds almost like you are torn between liking and disliking the term, but for totally separate reasons, which for the most part I agree with.
In this regard I agree with you. However, I LOVE being called slut. The reason being that I am HIS slut to use as He pleases. This doesn't mean that he loves me any less, or that I sleep around. Not at all. In our case it's almost a term of endearment. He uses it because I ask him to, because I want him to know that I enjoy being His & His only.
I think it's completely fair for you to feel this way. Many men (and women) are attracted to this lifestyle for this exact reason. I think there are quite a few men who fancy themselves 'doms' or 'owners' just so they can have their own personal sex slave. Being spanked does not make you a slut. In fact, just because someone calls you a 'Slut' it doesn't automatically make you one.
I'm sorry to hear that you lost your Master, but there are just as many Jerk-Face-Nilla's out there as there are in this lifestyle. Finding someone worthy of your needs will always take time, don't rush things. It's a matter of taking the time to get to know people and have them get to know you, too.
If name calling (or anything else) isn't your thing tell the person you are with. Any person you are with should have enough respect for you to listen and understand your concerns. S/he won't know until you tell them.
I'm going to end on this final note:
If someone just assumes you're a slut because you're a sub, write them off. They obviously don't know (or care) enough about you or the BDSM community to warrant your time. Alternately you could kindly advise them where to go to read up on BDSM roles before they inflict themselves on others.
Good luck & Be safe.
~ openlyrefined