The only thing missing for this to be correct is that, just like in English, after have as an auxiliary there's a participle. "Debí haberte hablado antes/ Debí haber hablado contigo antes". That said, they carry different meanings. The first implies "to you". (I should have talked to you before) so either there's something you have to tell them or you haven't spoken in a while... The second means "with you", so you are saying there's something you should have discussed. I hope this helps!

Hi again, Tom! To try answering your question: un pronombre reflexivo is only when the action affects the subject or the sentence. For example: yo me peino el pelo (I brush my hair), tú te peinas el pelo (you brush your hair). The one doing and receiving the action are the same. They're easily mistaken with the personal pronouns for the indirect complement, because they read exactly the same: me, te, le/se, os, nos, les/ se What you are using in your sentences is an indirect complement pronoun, so it's equivalent to "to you" or "to (person)". "Te" would be equivalent to "a ti" but "Quiero hablar a ti" it's /not/ a natural sentence. (However, Quiero hablarte a ti, is correct. A ti emphasises the person I want to talk to). Contigo has the sense of "with you". It carries a different nuance.