Another hubber said of a similar question that you must put in full time effort to create a full time income. With this in mind, there are a number of smaller goals that you must achieve for you to reach your goal of $3,000 per month. You need have to have many hubs, perhaps one, two or three thousand, preferably with evergreen content. After taking a quick peek at your page, you are on the right track with your hubs in this regard.
SEO skills are definitely very helpful however, that bar is constantly being moved. If this is something you enjoy, great but don't fret if it's not. Many hubbers don't pay much attention to this and are still earning money. Most importantly you will need thousands of views/reads per day to reach your overall goal of earning $3,000 monthly. There are a few hubbers that earn hundreds or more monthly and with proper effort, views and time, there is no reason you can't do the same.
Just do not expect to reach your goal in just a matter of weeks or months. I am earning more now after being here for a couple years than I was within the first year. Remain active. Even if you aren't posting new hubs there is a LOT you can do here such as ask or answer questions, engage in discussions, read other hubs, comment, etc.
Think about how you can get the word out about your hubs and increase your views. Keep writing and allow a significant amount of time to pass while maintaining your efforts. Remember there are smaller goals on the road to your main one and keep at it. Hubbing is an excellent opportunity to create a new stream of income. Best of luck to you.