Hi I've got these cracked lines and bumps on the penis head does anyone know what I should do?

Try moisturiser?

It's hard to say without a pic.  How old are you though, and how long have these lines and bumps been there?

If you want to add a pic, you need to be on a PC or laptop with a large window.  If you are, then you should see some extra icons towards the top right of where you type, and the right hand icon (which I think is supposed to look like the sun over hills) will add images.

The pic I've attached here shows the icons: 

It is most likely what you have is caused by something really simple, for example, have you been masturbating more vigorously and more frequently than usual?  The skin is really easy to damage around the head of the penis and this may be what you simply have.

I would recommend staying away from all oil base lubes and skin creams, ointments and baby oils and gels as this can lead to a dermatological reaction in the long-term.  Water based lubes and gels are better to find a one that you can buy cheaply and works for your enjoyment. 

In terms of the bumps, as the other respondents state, without seeing what these are, it is difficult to tell.  Obviously, I am only familiar with my own penis and whether such bumps were present or absent previously.  If you cannot photograph them, can you describe the bumps more precisely?  Size, color, are they itchy, or give you any pain?  If they get worse, what were you doing immediately before the bumps and lines got worse?  If you stop masturbating for 8 days to 3 weeks what happens to the bumps and the lines?  Try that .....