SoundsIt sounds like management has a problem managing your workload and prioritizing tasks. You should talk to your manager and make them understand that you are overloaded and you can't do effective work if everyone keeps bombarding you with requests which they want fulfilled immediately.
That makes you jump from one task and project to another, wasting a lot of time switching gears in your mind. For effective software development work, one should be able to immerse oneself into a task and focus fully on it. The more interruptions one gets, the more time is wasted by context switching. Research shows that it takes about 15 minutes to immerse and get to the state of flow where our mind works the most efficiently. If you get interruptions every 15 minutes, you never get to flow, which is a tremendous waste for both you and the company.
So you should try to negotiate a more sensible working mode with your manager. This should include prioritizing the incoming requests and planning ahead to some extent. All user requests should be maintained in a list, ordered by priorities. And the priorities should not be decided by the requester (as naturally everyone thinks his/her request is the most important on earth), neither by you, but by someone with enough business knowledge and overview of the whole range of products you are maintaining (the product owner).
Ideally, all incoming requests should be entered into an issue tracker like JiraJIRA or MantisMantis. Or at least mailed to the product owner, not you. And he/she should deal with all the complaints from the users too over "why is my request not ready yet?!", allowing you to focus on the development work. If this is unattainable, you should at least negotiate some windows of time when you look at incoming requests and deal with them, reserving an uninterruptible portion of your time solely for development.
If this is possible, the next step could be to plan ahead to some extent. I.e. That is, estimate the time needed to implement the top priority requests, then schedule your time into sprints, which may be one or more weeks each, and allocate enough tasks to the next sprint to cover your time.
You probably want to keep a portion of your time for incoming emergency requests, but the rest can be planned ahead. And you may also prefer to organize work on different projects into separate "streaks", i.e.that is, to work on Projectproject A on Monday, Projectproject B on TueTueday-WedWednesday, Projectproject C on ThuThursday morning and D on afternoon, etc., to further reduce context switching.
This way you have a rough idea of what you are to do in the next one or few weeks. Moreover, this gives a roadmap to your clients too: they can see when they get which request implemented. You may or may not want to mention the word "agile" to your manager here - this is basically agile development, but some people oppose Agileagile without actually knowing what it is :-)
Note that even if your current position seems low valued by your company, the more projects you are maintaining, the more negotiating power you have.
Finding and training a new hire to maintain all these projects takes considerable time ( = money) for the company. And you may rightly point out that your code is so much better than the legacy parts of these appsapplications, so it is not a given that they can easily find a candidate of similar capabilities for the same amount of money. Not to mention that if they don't improve working conditions, they will make the next guy get fed up and quit just as fast as you... Try to make them understand that it is in their own best interest to keep you, and to keep you happy where you are :-) This may give you some power to negotiate the above conditions, and/or request a pay raise.
How much negotiating power you have - that is a big question. Your management may or may not be open to these ideas, and may or may not respect you enough to take your pleas seriously. But if you play your cards well, you have a chance. And if they refuse... you can always look for a better workplace. This situation isn't the same for every starter, although (sadly) your experiences are fairly typical. But there really are better workplaces out there. QualityThe quality of workplace is only loosely correlated with geographical location, but my feeling is that in Northern Europe you have higher than average chances. So if you can't get your current conditions noticeably improved, you should start looking immediately, before you get completely fed up, and burnt out.
It is immensely better to look for a job while you still have one, so you need not accept the first offer just because you need money immediately. Eventually you will find a better place :-)