You can't predict your parents' thoughts or reactions or do anything about them. If you want something, ask for it. Keep things simple, "I'd like to go see the social worker (or "someone") again for a bit of counseling; I have (and accentuate the "I") a problem I'd like to discuss with them." Keep it "tight" and don't leave any room for "last time I checked. . ." and just keep with "there's just something I'd like to discuss" if they ask "why" or "what's wrong", etc.