Need Legal Advice

good day!

i am a single mom for almost 5 years now though, legally married. i just wish to ask and seek legal advice because i would like to prepare an affidavit of abandonment to be signed and attested by my ex-husband. would that be ok? i was also advised before to prepare an affidavit of three (3) witnesses just in case I would decide to file for nullity of marriage. For now, all I would like to file is the affidavit of abandonment, how should I do it? Another thing, would it be possible to change my son’s surname which is his legal father’s surname, to my own surname? Please assist me in this regard. Thank you so much!
[b]

may i ask who advised you to execute an affidavit of abandonment?

A family friend who’s also an atty. He told me before that I should’ve filed a complaint or a case before, when the actual physical abuse was happening to me and to my son but I don’t want any scandalous scenario that’s why I kept silent for almost 7 years of my marriage.

Anyway, I have also consulted before regarding the nullity of marriage, but since it would be too expensive to file I choose not to go with it. My only concern right now is the right of my ex-husband over my son. Please help me how I can remove his right over my son. He is currently with another girl and I don’t have any comment regarding that, I just want to clarify to him that he is waiving or removing his right over my son. I also want to ask, is it possible to change the surname of my son from his current which is his father’s, to my surname when I was still single?

Another thing, a family friend also suggest that I should consider preparing 3 witnesses w/ affidavits about what happened to me and my son because that would be of help if I would consider filing a nullity of marriage. Should I take that advice?

Thanks so much! Honestly, I was seeking way too long for someone whom I can really ask for legal concerns. I do hope you could help me.

Thanks again and God bless!!!