Asalaamualaikum. I know there is a lot of debate about art and islam. When I heard art is haram I stopped drawing but it's made me really sad. I don't know what I can and cannot draw and it is very confusing. Is it ok to draw on my computer if I do not post it online and do not show it to anyone? Will Allah punish me on the Day of Judgement for my past drawings? What objects do and do not have a soul? Is it okay to colour in a colouring book?
If it's animate beings than it's haram, whether it's digital art nor not. Even if your drawing/art doesn't contains nudity or idol worship it's still considered as haram. There are many hadiths for this. The hadith doesn't say that if it's not about idol worship then you can draw it. and this is one of them.
... "The makers of these pictures will be punished on the Day of Resurrection and it will be said to them, 'Make alive what you have created.' Moreover, the angels do not enter a house where there are pictures.'"
Ibn 'Abbaas (may Allaah be pleased with him and his father) reported that the Prophet (peace and blessings of Allaah be upon him) said: "Every image-maker will be in the Fire, and for every image that he made a soul will be created for him, which will be punished in the Fire." Ibn 'Abbaas said: "If you must do that, make pictures of trees and other inanimate objects."
(Reported by Muslim, 3/1871)
These ahaadeeth indicate that pictures of animate beings are haraam, whether they are humans or other creatures, whether they are three-dimensional or two-dimensional, whether they are printed, drawn, etched, engraved, carved, cast in moulds, etc. These ahaadeeth include all of these types of pictures. Islamqa.info
Tress, mountains and other inanimate things can be drawn.
The Muslim should submit to the teachings of Islam and not argue with them by saying, "But I am not worshipping them or prostrating to them!" If we think about just one aspect of the evil caused by the prevalence of photographs and pictures in our times, we will understand something of the wisdom behind this prohibition: that aspect is the great corruption caused by the provoking of physical desires and subsequent spread of immorality caused by these pictures. Islamqa.info
No you'll be fine. The reason that it was prohibited was because people turned these idols into forms of worship over hundreds of years. You are not creating anything that will go public, and certainly not anything that will become an idol over time.
All the hadith on the issue were for specific instances and definitely do not apply to our situations where TVs are every present, billboards exist, there is art in everything from cartoons to advertisements to the logos on your laptop and mouse. Don't worry my sister your intention is pure and there is no problem.
And Allah knows best,