Hello Usitha,
Welcome to the forum! Glad to hear about your progress.
Yes. Any current suffering via the body is due to past kamma. We need to bear any such suffering with upekkha. Of course, one MUST engage in all possible remedies like medical help, good exercise, healthy foods, etc.
As you said, it is smphassa-ja-vedana or the vedana that we create in our minds that lead to FUTURE suffering.
– Yes. We create them because of the ignorance (or absence of full clarity) of the anicca, dukkha, anatta nature.
Yes. All mental dukkha vedana (domanassa vedana) are mind-made or smphassa-ja-vedana.
By the way, the steps in the Paticca Samuppada need to be understood in this wider context.
The “uddesa” version is: ““avijjā paccayā saṅkhāra; saṅkhāra paccayā viññāna; viññāna paccayā nāmarūpa, nāmarūpa paccayā salāyatana, salāyatana paccayā phassō, phassa paccayā vēdanā, vēdanā paccayā taṇhā, taṇhā paccayā upādāna, upādāna paccayā bhavō, bhava paccayā jāti, jāti paccayā jarā, marana, soka-paridēva-dukkha-dōmanassupāyasā sambhavan’ti”
In the “niddesa” or “expanded” version: ““avijjā paccayā abhisaṅkhāra; abhisaṅkhāra paccayā kamma viññāna; kamma viññāna paccayā nāmarūpa, nāmarūpa paccayā salāyatana, salāyatana paccayā samphassō, samphassa paccayā smphassa-ja-vēdanā, smphassa-ja-vēdanā paccayā taṇhā, taṇhā paccayā upādāna, upādāna paccayā bhavō, bhava paccayā jāti, jāti paccayā jarā, marana, soka-paridēva-dukkha-dōmanassupāyasā sambhavan’ti”
“Uddesa” and “niddesa” levels of explanations are important in sutta interpretations too: “Satipaṭṭhāna Sutta – Structure“