spelling words :(

I am 17 years old and i came from a different country and lived in England for 6 years Now as aim in collage i require a high level of English language and at least knowing how to spell. i do lots and lots of spelling mistakes and for some reason i feel aim becoming worse and worse every day.
i try best to read books but you know A levels dost leave you much time
I am going to develop my spieling and the knowledge of English over the summer holidays any tips or apps i can use that will help me... i want to develop my spelling. i want to do do it as fast as i can any tips on how to improve myself please any will be helpful. ):
Already made 17 mistakes but fixed by spell check... i feel so unhappy because of that and ashamed ... sometimes i write something to some people and they make fun of me "is this 5 years old typing"
so please help

Hello, Coventry University Student Ambassador here!👋
Being an international student, I wholly understand your struggle, and the stress of not being unsure of your language skills are. It takes a lot of time to master a language and it can be daunting, however I found that stepping out of my comfort zone worked best for me, as well as a couple of techniques such as:
Reading Regularly - Exposure to well-written material helps reinforce correct spelling. Read books, articles, and other literature regularly.
Writing Frequently - Practice writing essays, stories, or even daily journals. Pay attention to spelling while writing.
Use Spelling Apps and Tools - Apps like Grammarly, SpellCheckPlus, and websites like Merriam-Webster offer spell-checking services and exercises. But DON’T be dependent on these!
Memorize Commonly Misspelled Words - Create a list of words you often misspell and practice them. Use flashcards or spaced repetition systems like Anki.
Engage in Spelling Games and Quizzes - Play games like Scrabble, Boggle, or use online quizzes to make learning fun and engaging.
Break Words into Syllables - Breaking words down can make them easier to spell. For example, “necessary” can be broken into “nec-ess-ary.”
Practice Phonetics - Understanding phonetic spelling can help you spell unfamiliar words by sounding them out.
Use Mnemonics - Create mnemonic devices to remember tricky spellings. For example, to spell “because,” remember "Big Elephants Can Always Understand Small Elephants."
Hope this helps!
Bianca