Why do you think you're an ISFP? 8w7 is potentially the most extroverted/outpoken of all enneagram combinations. For an ISFP to be one, they would have to disregard their first function and may be in a perpetual Se-Te loop. But that could be explained easier by saying they're an Se dom who's moving to their third slot Te (ESFP). It's not impossible, but the person must be in so much distress.