To improve your rating in chess it is necessary to deepen your understanding of chess positions.
1. Specialize in some selected opening systems and study them deeply. You have to buy chess books about your openings and study each opening to understand its positional ideas. After that play the same openings all the time and when you lose study your mistake and play the variation better next time if the mistake was done in the opening.
2. Chess is all about position, tactics is overvalued. Only weak players think chess is all about tactics. This is wrong.
If you can't play good positional moves because you don't understand the plan in a particular position then your game will always get worse, slowly, but surely, and you will find yourself always in an inferior position.
How can you win then? This is impossible unless your opponent makes a patzer..
In a bad position all tactics usually are favourable for the player who has the better position.
Simple logic. How can you expect something else?
If your pieces are badly placed how can you apply good tactics. This is usually impossible and against all logic.
Get books about chess strategy and study positional chess. Play 1.d4 as White all the time. This leads to a more positional game.
Study all systems that Black can play after 1.d4 (Nimzo-Indian, Queens-Indian, Queens Gambit, Slav Defense, Kings-Indian, Benoni Defense, Dutch)
If you don't want to learn all these openings then cut down as White and AVOID some systems from Black.
Example: Play first 1.d4, then g3 and Bg2 and c4 much later to avoid the Nimzo and Queens gambit ... There are books about this. Or play the Catalan as White only.
Whatever you do, play the game in a strategic way and get books about this.
For example: As Black you can start the game with 1..d6 against all openings from White. This forces your mind into positional thinking. You can buy a book about this. (Modern Defense) The game gets very positional after 1..d6 which will improve your positional understanding.
Example: there is book from Cyrus Lakdawala called: 1....d6 move by move. Such books will teach you how to play in the unusual positions that are evolving after 1...d6.
To study similar books (about modern defense) are very helpful to improve your positional approach.
I know a player who is specialized on 1..d6 as Black and plays 1.c4 (the English) as White all the time. This way he just has to study the English as White and the Modern Defense as Black. He saves a lot of time this way. He has many books about the English Opening and the Modern Defense and has studied them all.
I am sure your rating in chess will get better when you approach the game in a more positional way.