Can't get past 1400-1500 elo.

Chess is extremely hard! Many people don't improve past their first big plateau. You certainly can, but it takes effort to do so, and that effort is not for everyone.
I take it that you're pretty young and if that's the case I wouldn't sweat it, since just by playing a ton you'll gradually get some more experience and become stronger.
But if you want to improve more quickly than that, it'll require some more focused study. Analyzing your own games is very important. Also you need to practice both calculation and pattern recognition. I always make sure my students understand that there are multiple categories of "tactics training" and that both are very important.
Wrt "method to calculate," I'd say the first step is to ask yourself what the opponent's threat is. "What's he got, and do I care?" is the question I was always taught to ask.

Even I felt stuck when I was 100. Like I would never improve, but then I started winning. Dont worry, youll get better

I've got two suggestions:
Firstly, Tactics! I know its the same advice you get everywhere but you really need to improve your calculation to get past 1500. I suggest the "Woodpecker Method" for studying tactics. First, get a PHYSICAL tactics book. Training with a book greatly reduces distractions and helps prevent you from going on discord or whatever. I used Susan Polgar's Chess Tactics for Champions. Once you have the book, at least a few times a week, start at the beginning of the book and solve as many puzzles as you can in 1 hour. Eventually, you will be able to get further and further into the book.
If that doesn't work for you, do at least 30 minutes of puzzle rushes or puzzle storms per day for at least a month. After you do this, you will be able to calculate much better.
Above all, don't get discouraged! Chess is a hard game, and it's normal to have plataeus.
Finally, one more piece of advice: Try to play some rated OTB tournaments if you have time, they are fun and are extremely helpful for higher-level improvement. It's hard to become a strong player without playing over the board. If there aren't any near you, consider organizing one. It is well worth it from an improvement point of view, as well as being lots and lots of fun.
Edit: Don;t reply here, got the solution