If you are sticking with one source of income, it is either you would strive for a higher position or higher salary to afford things. Another option is to adjust your expenses for things to be enough given the circumstance of only having a single source of income. But personally, eversince I started working, I never settled with a single stream of income. Well, yes, it is sometimes tiring however if you desire of more things then you should move more. Nothing's easy when it comes in life so better make the adjustment to serve the purpose you always wanted. You could start with learning new set of skills or things which may increase your credentials and/or the things you could offer in order to simply earn more. Again, this is an option if you no longer consider having two sources of income. It aso depends on what would work best for you given that we are living under different circumstances. Some people are okay with one job, and that's just fine. What matters is being able to suffice your daily needs and being able to save up for future nd emergency purposes, even little by little.
Having one source of income means you either have a well paid job or have a high position at work. The current economy of the country doesn't exactly encourage having just one source of income with the fluctuating value of naira and constant increase in prices of commodities, having just one source of income isn't advisable because as you are living in the present, you plan for the future. You can't spend all your earnings at once without having a savings plan and if your current income only provides for your basic necessities, how do you plan on starting a savings plan?.
However, with proper management and priorities one won't need to work two jobs just to meet your responsibilities.