"This on earth" - "Lenei i le lalolagi".
Ta'amilo i le lalolagi
O le lalolagi o lo oe.
Earth as the world is "Lalolagi"; earth as in mud, soil, is "palapala".
"Mo le lalolagi, o oe o seisi/se tasi - ae mo seisi/se tasi, o oe o le lalolagi." Somebody and someone translates to seisi or se tasi.
I think what you're saying is, "Only you for me in this world" or "You are the only one for me in this world".
Teine/Tama'ita'i, o oe o lo'u lalolagi, ma le tasi, na'o le tasi lava.
lou ola (your life), lou lalolagi (your world), o au mea uma (your everything)
Alsowe is not a Samoan word.
Olive is also Olive in Samoan.
Titi in samoan means tiny.
Thats not a Samoan word. It sounds Hawaiian or Rarotongan maybe? Definetly not Samoan.