Hi,
Its great that you do not have habits that hamper your health and sexual performance. And you seem to be lean person - at least not obese - at 6 ft ht and 65 kgs. weight. These are positive factors for good sex life. But I suspect that you are too anxious about the penis size that erections are also affected which in turn increase anxiety.. in a vicious cycle.
Next Steps
You would benefit from direct consultation, where we can elicit relevant information from you, alleviate your concerns and offer medicare if necessary. SInce you said you have frequent urination, you need to be tested to rule out high
sugar and UTIs