Suggest Remedy For Weak Erection And Premature Ejaculation

Hi My name is addie i am 24 year old guy and i am single, from a week i am facing a problem of soft erection and sort of premature ejaculation, because now day when i trying to masturbate,first i found hard to get an full erection and when i got 90% erection i ejaculate.I do not know what is this, because i continuously doing the PC muscles exercise form past 3-4 month, before 2 week my erection was good and do not fell like now.from 2-3 days i continuously feeling the urge of pee or something i urge to get out from my penis little with tickling and burn.want to tell u one more thing before this situation, i use-to massage my penis but when i about to ejaculate by squishing my PC muscles i hold the ejaculation and stop massaging i hold my cum inside, so tell this harmful or i am facing this problem due to poor diet or wrong exercise of penis plz help me,