if youre playing ranked maps to improve, you're just setting yourself up for disappointment. the biggest piece of advice i could possibly give you is avoid the ranked map category for practice- the only things that get ranked anymore fall into 1 of 3 types of patterns and are generally far easier than their star ratings would imply-
given youre in the 4digit range, you've got quite a few options available. First off, i'd recommend trying Etterna if you havent already, it will do wonders for your accuracy and consistency as well as provide you with a means to break out of any bad habits you've likely built on osu!mania as well as help you identify where your strengths and weaknesses are through a better variety of charting styles.
additionally, in terms of osu maps, multiplayer tends to be a great way to find valuable practice maps that would never be able to get ranked but are important for developing your overall skillset.
Lastly, don't underrate the importance of accuracy training. it wont give you much pp or improve your rank, but dont neglect 2-4star maps in your play; going for SS, playing with hardrock, and improving your MA and PA will do wonders for your overall consistency, especially as you are playing harder maps.
Ultimately it will be up to you to analyze your play and build an understanding of where your weaknesses lie, but step one is moving away from the ranked map pool for a while