Firstly, having a goal has a point if it motivates you to read more. If it stresses you out, then it will be just another obstacle you will have to overcome to motivate yourself, and therefore is unnecessary.

Secondly, goal of 50 is absolutely not small, especially if you are new to reading and additionally have other things going on!

What may help:

• If you still want to have a goal, set yourself a goal that motivates you, instead of feeling overwhelming. For example, 12 or 24. This way, you will still have something to strive to, but at the same time it will feel attainable and will give you freedom to experiment with different books & authors. Instead of having to read for several hours a day, it will be enough to read 15-30 minutes.
• Read short stories, short novels or collections. It is great way to discover authors, writing styles and genres that you like without having to commit to the whole book. Additionally, it will give you feeling of accomplishment.
• Try reading and listening to audiobook at the same time. It has been recommended in this sub several times and seems to help with getting distracted.
• You may also try comic books. There are several great ones such as Sandman by Neil Gaiman or Watchmen by Alan Moore.

It may also help to understand how you choose books. For example, I tend to choose based on my mood and mindset which means that if I choose something that doesn't fit aforementioned, I will struggle with getting into it and it will feel more like a chore.