Add one line to the cell when enter is pressed - php

Question

So I just detected a problem on my fpdf, when I'm writing the description to the multicell I press enter to break line and this happens
Image with problem
but my multicell code is programmed to calculate the string size and when the size is bigger than the width of the cell it ads one break line and the height size gets bigger but when I press enter it just add the same height
example
"My name is João" -> height = 6.5
"My name is João, (line break) I'm using fpdf" -> height = 6.5 + 6.5 instead of height = 6.5 + 1
this is my pdf without pressing enter
Image
this is my pdf with multicell on action
Image
I will leave the code that it's calculating all the multicell stuff.
$size = $pdf-> h; // page size
$cellWidth=120; // width da cell
$cellHeight=6.5; // height da cell
// verificar se o texto passa a cell
if($pdf->GetStringWidth(iconv('UTF-8', 'windows-1252',$r['description'])) < $cellWidth){
//doesn't do anything because when line is multiplied it receives the same value ( 6.5 * 1 = 6.5 )
$line = 1;
}else{
$line = ceil($pdf->GetStringWidth(iconv('UTF-8', 'windows-1252',$r['description'])));
$line = round($line / $cellWidth,0) + 1;
}
// use multicell instead of cell
// as a MultiCell is always treated as end of line,
// manually set the xy position to the next cell being next.
// save a position x before writing a multicell
$xPos=$pdf->GetX();
$yPos=$pdf->GetY();
$total = $yPos + ($line * $cellHeight);
if ($total > $size - 30) { // $size = $totalheight // change page
$pdf->AddPage(); // add page
$xPos=$pdf->GetX();
$yPos=$pdf->GetY();
}
$sizecell = $pdf->GetMultiCellHeight($cellWidth, $cellHeight,iconv('UTF-8', 'windows-1252',$r['description']));
$pdf->MultiCell($cellWidth,$cellHeight,iconv('UTF-8', 'windows-1252',$r['description']),'LBR','L');
// receive the position of the cell after multicell
// equals the x with the height of the multicell
$pdf->SetXY($xPos + $cellWidth , $yPos);
// write cells
// as the variable $cellHeight is multiplied by the value of the line is going to be greater than $cellHeight
// of the multicell so we need to make a loop and subtract 0.01 until the value is the same as the multicell
$cell = $line * $cellHeight;
if ($cell > $sizecell){
while($cell > $sizecell){
$cell = $cell - 0.01;
}
} else {
$cell = $cell;
}
$pdf->Cell(15,($cell),$r['quantity'],'LBR',0);
$pdf->Cell(10,($cell),'UNI','LBR',0);
$pdf->Cell(25,($cell),$r['priceuni'].chr(128),'LBR',0);
$pdf->Cell(25,($cell),$r['sum'].chr(128),'LBR',1);
I accept any suggestions, I have no idea of how am I going to do this