Lump in mouth. Hasn't gone. i'm worried.

The lump in the floor of the mouth seems like a ranula, going by the description that you have mentioned. A proper clinical examination will be required to confirm this diagnosis, which remains tentative till that point. The pimple on the upper lip could be something else but it is highly unlikely that it is related to the Ranula. These are two independent problems occurring concurrently at the same time. It is also less likely that the ranula is going to resolve on its own without some intervention by an oral surgeon. So it would be prudent if you make a visit to the dentist as soon as possible. And as regards the habit of smoking, you do realise how dangerous it is and if you are now worried that the potential harmful effects are starting to take shape, you should quit this habit immediately. Regards.