I've had swollen lymph nodes for years in my left groin and right jaw. Doctors seem to dismiss these things as common and harmless but I now strongly advocate that all these seemingly trivial and common symptoms are puzzle pieces to a larger picture. The immune system is fighting, but not getting what it needs and is blocked up. I believe learning to ask questions just like you're doing begin to train us to ask the RIGHT questions.
Why is the immune system working so hard? Your guess at Candida is a likely answer. I did finally have a SIBO (Small Intestine Bacteria Overgrowth test)that revealed I had Candida overgrowth there. So I went down the path of anti-fungals and restrictive diet. This helped, but other signs in my body prompted me to keep asking more questions. Candida, bacteria and parasites, etc. go hand in hand. While measures to eradicate these things are likely needed, sometimes the protocols or our efforts end up also stripping the body of other nutrients it needs. After all these years my swollen lymphs have moved and are almost entirely gone. What I discovered along the way is that Candida, parasites, and bacteria also bind to other toxins like heavy metals and so this was an extra piece of the puzzle that needed addressing for me. While detoxing and chelating, etc., I also had to find the right nutrients with other supplements because as clean as my diet was, there was absorbability issues and the healthy food wasn't enough to help remove the toxins.
Normally the body has many routes for elimination: the obvious bowels and urine, but also proper sleep, relaxation, and reduction of stress. All these occur in the parasympathetic nervous system which is where the body repairs itself and heals. Digestion also happens with this para nerv sys. Another way the body naturally detoxes is with an exhalation (and again it makes sense that we need to be able to inhale/take in what we need, in order to fully exhale/expel what's not needed). I have noticed with myself as well as others an impaired ability to breath fully and freely. But sweating is another natural detox. So I'm interested in how your lymphs would swell after exercise (skeletal-muscle contraction, ie. movement is what moves lymphocytes in the body). Was your body trying to eliminate but couldn't? Were you able to sweat during your activity or did you just get kind of flushed and a red face, etc? Is there an odor to your perspiration? I believe questions will continue to lead you to answers.
About the kink and tingling below your left ribs- could be the spleen (also immune system) and depending on where exactly you feel this point, another possible explanation according to some alternative schools of thought might suggest low stomach acid. You can easily do a search for low stomach acid and see if anything seems to fit with you. A natural supplement for this is called HCL -Betaine. This may relate to candida, bacteria, and parasites, etc.
The lymph system is just below the layer of skin and so there are other dry-brushing and stroking techniques that can be done to promote the flow of toxins through the lymphs. Some massage therapists offer these techniques as well but you can also easily watch a quick youtube video.
Taking showers and going cold to hot etc. also stimulate your immune system and the flow. Many folks seem to advocate the far infared saunas as well to detox toxins, etc.
Hope this helps and good luck on your journey. Keep asking questions because sadly your doctor hasn't been (and sadly all to many of us have the same experience)