APL (Dyalog Extended), 189 bytes^SBCS

Full program. Prompts for the Morse code. Doesn't need the library.

⌊⌂morse⍞⊂⍨∊1↑⍨¨1+,4⊤'⍳÷+≠í⍀÷<í∧○Ñ>å/∧∨êî∘ß∧äñ⍀○≠è[*⌷∨[î≠∇è⊂Øî⊃⍀[⌷Éäï\∘∧↑æ=íå⌿∧∨ëäÖ⌿ê/≤⌊∘[Å↓Öï○+Ü÷≥↓≤≥>⌷∘á⊃↑Ü⍳⊣[⌿-Ø↑ä/∧∧≠≠Ñíí+ßÜ+-○é↓↓≥≥×∧↑**⍨↑}∧⍨≥ç⍀∧}×⍀Àëç⍀Ø⍨∧∘[×/∘Å∧~≥○ëâ⊂å∨≥Àäè?'⍳⍨125↓⎕AV

Try it online!