I feel a tightness during prayer or ablution, so what is your opinion on this?

Prayer and ablution are two causes for the expansion of the chest and the tranquility of the heart, and they are not a cause for distress. What the questioner finds of distress is from Satan, who wishes to alienate him from obedience. He must strive against Satan by fortifying himself with the recitation of the Quran and the consistent practice of remembrances (dhikr).

The questioner should also be keen on achieving devotion (khushu') in prayer and reflecting on what he says during it, so that it becomes lighter for him and he loves it, and it becomes the delight of his eyes.