Can we address ourselves as "Mr." for men or "Ms." for women?

No. In polite conversation one should  not use any titles, like, Mr., Ms., Mrs, Dr. Prof., etc. to introduce oneself. The reason is, it sounds boorish and rather displays arrogance in one's attitude.

No, cos you can never address yourself, it would look and sound a least weird

No. Its for others to introduce or address you as Mr or Mrs. or Ms. and surely not for self.  Thanks.

Thank you guys for your sharing, I really appreciate it.

siding with expert opinions

Yes, Ms. Used For a single lady and Mrs for a married lady, I always use Ms to address myself to other people who are not close to me as strangers or individuals I meet for first time but with friends i use my name Rima without Ms.

Thanks for the invite and leave the answer for the professionals

In my business life, I never use or I did not see anyone used yet. as per English grammer also, one will use for himself this types of honorifics. So, simply and polite way, no one will use it.

We use "Mr" when calling a man ,other wise we use "Mrs" when calling a lady

 I leave the answer to the specialists the experts in this the field .

A good views are given by experts but I have a little bit different worldview. Pardon me, In essence, history and etiquette tell us that Mr. , Mrs. and Ms. are the proper form of address for men and women, yet beneath the surface of these everyday honorifics, there are many secrets on people communication forms .Let's know some! In the workplace, people usually call each other by their first names, with no title, that's even true in written email communication, and even when you're speaking to someone from another company. nonetheless, I think that, calling a person by their title seems formal and creates a distance between people, yes I know but sometimes I really like to do and meanwhile under certain circumstances I could use a little of that attention myself as Ms, or Mrs. to others. I normally use these titles with my last family name in formal letters and I often use a title plus my full name ("Mrs." or " Ms) at formal events like political forums, business meetings and graduation ceremonies, but with close Friends and family members almost never address myself with a title, except perhaps I want to keep a distance between me and the other party.