What is the solution to the problem of speaking loudly during sleep and feeling a tightness in the chest, while waking up without remembering anything, and what is the effect of combining prayers due to work circumstances on this problem?

If the mentioned events occur while awake, they are waswas (whispers from Satan or obsessive thoughts), and their remedy has been mentioned in previous fatwas. However, if they occur in sleep, they are mere nightmares (adghath ahlam), and it is sunnah (definition) (recommended) upon waking up to spit three times to the left and seek refuge with Allah from their evil. Difficulty breathing after sleep is the jathum (nightmare/sleep paralysis), and to understand its nature and treatment, one can refer to fatwa (definition) number: 52747. As for combining Dhuhr and Asr prayers due to hardship and difficulty, it is permissible according to some scholars, but habitually doing so is considered a dereliction in religious duty. The obligation is to take precautions to perform each prayer before its time expires, while avoiding hardship. If combining is unavoidable, then it should be a "formal" or "apparent" combining (meaning performing them consecutively within the time of one, but without formally altering their individual times or conditions).