Relax sir...
Don't be hurried.. get treatment for underlying causes.. premature ejaculation and erection are secondary if u r having psoriasis complaints.. y because psoriasis trouble u both mentally and physically.. if u r not comfortable u can't able to sustain erection and as well as u can't able to enjoy the sexual life.
Next Steps
consult a good homeopth and get eradicate ur psoriasis first..
Health Tips
avoid suppression by external application and steroids..