quite freak out what's wrong with me

Hi, I'm 25 male and I got these symptoms for the last 2-3 days:

• Intermittent shortness of breath / breathing feels “not normal”
• Able to take a deep breath, but breathing sometimes feels unsatisfying or different
• Gets short of breath more easily with walking or light activity
• Muscles feel tired/fatigued more easily with activity
• Moderate cough
• Sensation of something “stuck” or tight in the throat
• Stomach bloating/fullness throughout the day

Doctor visit (yesterday):

• Blood pressure: 120/83 mmHg

• Doctor listened to heart and lungs, including with deep breathing also looked at my throat and he said nothing, just infections

• Nurse used a finger pulse-oximeter, presumably measuring oxygen saturation and pulse. No abnormal oxygen reading was mentioned

I'm still quite worried with all these symptoms, can anyone help me with this ?