Will the Botox slow the healing process or cause complications to my wound? (Photo)

Botox should not affect the healing of your forehead wound.  The Botox partially or completely immobilizes the muscles.  It does not affect the skin or the blood supply.

While Botox will not interfere with wound healing, most injectors will forego elective injections around open skin for fear of infection.  It sounds like you had Botox prior to your cut; that shouldn't be problematic.  Without knowing how old your laceration is, you may benefit from either sutures, taping, or keeping the laceration moist now, and regular sunscreen and taping the cut after it heals.  I suggest you call a few plastic surgery practices in your area to seek further advice about your laceration, as I would argue that repairing the laceration and getting it to heal well takes priority currently; most elective laceration repairs can run the cost of a Botox treatment.  Good luck!