I'm so sorry you're going through this, person. You haven't said, but in addition to being seen at urgent care two days ago, I assume that you've been checked out and that "they can't find anything wrong" to explain your pain. We do always advise that you have ruled out any physiological explanation for your symptoms.
That being said, a few things occur to me which I think might give you hope:
1. An increase in symptoms after learning about TMS is not only a very common experience, it is also proof that your symptoms are TMS. What other possible explanation can there be for a sudden increase in symptoms that occurs just after learning that you might have repressed emotions? The reason for this is that your brain is desperate to keep those emotions repressed! This is a very primitive mechanism that our brains are still using, although the original purpose doesn't make sense in today's world. We would all be healthier if we faced our negative ugly emotions head-on, and realized that they aren't the end of the world. But our primitive brains aren't that intellectual. Your brain thinks it's doing you a favor by keeping those negative emotions repressed, because it's afraid that something terrible will happen if you're distracted by them. Instead, it gives you pain which will supposedly distract you in a much more alert way.
Remember, all pain signals are created in the brain - they do not originate in your body parts. Your brain creates pain, and it can do so even though there is no physiological reason for pain.
2. Neuroscientists tell us that our brains are also wired to be negative. We're constantly scanning the horizon for danger, which is another primitive mechanism that does not serve us well in the modern world. Taking a walk, as you did the other day is a commendable action, but your brain has a deeply-programmed pattern of viewing this activity with fear. You've got to break that pattern. So the next time (and there will be one!) try doing a little meditation, or some positive affirmations, or a positive visualization, or any or all of these things, before taking the walk. What you want to do is calm your brain down, and prepare it for the experience of taking the walk without advance fear of something bad happening. Even if you have some pain, it doesn't have to be crippling pain. YOU have the power to change your experience.
3. We've seen descriptions of unbelievable pain suffered by people who found relief by accepting that their pain was TMS, and who did the emotional work needed to overcome it. Steve Ozanich who wrote The Great Pain Deception was easily as crippled as you are. Steve posts here regularly, by the way.
4. See if you are able to practice some self love. You are probably beating yourself up and I expect there is a lot of negative self-talk going on inside your head (and I am expert on negative self-talk). See if you can listen to that, and break into it with a different message. Like giving yourself credit for being open to the theories of Dr. Sarno. And for taking a risk by posting on this forum. And for being on Day 3 of the SEP. For taking action. And as you get better, you will be able to raise your child with a new level of knowledge that you never had - that's something to look forward to!
5. Along with doing the daily SEP, it would help to be reading something else. For anxiety, I recommend Hope & Help For Your Nerves by Dr. Claire Weekes. For more up-to-date information about TMS and its many equivalents, The Divided Mind by Dr. Sarno and six other medical professionals (five of them MDs). For pure guts and inspiration, Steve Ozanich, The Great Pain Deception. Read other posts on the forum, because there are more resources out there than I can ever remember, and there are also more ways of doing this work than can possibly be listed in one post.
We're pulling for you, so hang in there. And be good to yourself.