I'm in my last year of undergrad and am entering a Counseling Psychology PhD program this fall. Going straight to PhD from undergrad without working or getting a Master's in between can be difficult, but it is certainly still possible. As other users said, make sure you have lots of relevant research experience in your area of interest to create a cohesive narrative for yourself and your academic path. Continue finding relevant summer internships as well.
My experience with TC is limited and, admittedly, unfavorable. I was offered an interview, but I didn't want to book my travel without making sure TC was still a competitive option for me since I had other offers, so I reached out about 2 weeks before the interview to inquire about potential financial packages. The Insider's Guide said only 66% of students had assistantships, or something like that, and I was unsure if all students received tuition remission since it said nothing on their website about this, so I asked. I waited ~2 weeks, sent follow-up emails, and never got an answer other than "I'm waiting on info," so I withdrew my application the night before the interview (yet they still sent me a rejection this week...). With my friend dropping out of their EdM program because it was too easy, TC rudely "congratulating" PhD applicants for getting into their EdM program in past years (see Results in 2012 and 2013), inviting lots of people to interview just to advertise their EdM program, two of my professors speaking poorly of the program, waiting 2 weeks for no info, and their apparently non-competitive funding, it made the decision easy. But that is just my experience - perhaps yours will be different, and I bet there are current students who have had positive experiences with TC, so don't let mine influence you too much.
Good luck! Feel free to ask me any questions if you have them.