What is the dosage of Dapoxetine for premature ejaculation?

Hello doctor,

I am 45 years and suffering from severe premature ejaculation (cannot sustain for a minute or two) and mild to moderate erectile dysfunction (less hardness and short length after erection, difficult penetrating other than the missionary position, long delay in repeat erection) since the beginning of my sexual life. For last few years, I am taking Dapoxetine 30 mg (Duralast 30) before sex. It gives me a bit control but as I find 30 mg not much effective so I started taking two pills of 30 mg sometimes together and sometimes after a gap of 3 to 6 hours. Occasionally, I also add 25 mg Sildenafil or Tadalafil 20 mg (Tazzle) for improving erection. My problems are as under:

1. I find Dapoxetine 30 mg not effective but when I take two tablets, can control the ejaculation in a better way but has nausea feeling and low libido. I also feel too hungry after 1 to 2 hours of taking tablets. Besides even two tablets has effect for 2 to 3 hours and does not remain effective if sex is delayed. Now I started giving a gap of 2 to 3 hours between two doses of 30 mg which reduced the side effects. Is this pattern of dose fine?
2. Is there a probability of any longterm effect of taking 60 mg daily dose of Dapoxetine?
3. As most of the time one cannot fix the time of sex in advance as it depend upon the mood of the partner too. So Dapoxetinecannot be used as a curative medicine to improve the condition permanently or it is only SOS?
4. How can I reduce the side effect especially of low libido and nausea?
5. Effect of sildenafil remain a bit longer and help in erection even for two days of taking the tablet. What is your recommendation of doses? How to enhance the length of the penis as my penis face difficulty in reaching partner’s G spot and it reaches to full length only just before erection. Please advise a remedy.