Your opening was good, I don’t really see any issues, and you can often play faster in the opening because they are just principled moves. By move 18, you had a very good position, over 16 minutes on the clock, and some very good developing moves available (such as 18. Rd1, attacking the queen and seizing an open file. Alternatively, you could make a luft for your king to kill any chances of a backrank mate). However, you spent a grand total of 7 seconds sacrificing your Queen with 18.Qe8+ going for backrank mate, failing to calculate that after 18…Rxe8 19.Rxe8, your opponent can just play Rf8, and now you are down a queen. There is nothing wrong with mistakes, that’s how you learn, but you should spend more time in critical positions analysing ahead (especially with sacrifices). I reckon if you’d spent 30 seconds rather than 7, you would have seen your miscalculation.
TL;DR: Please take some time to think over your moves unless it is obvious or you have already calculated the line beforehand. At this speed you are basically playing a blitz game, rather than 15+10.
while im getting elo i improve along the way, i play games everyday and after playing some games i watch ed vids, practice middlegame ideas, and much more. Its just because while im trying to improve. When i play games. my elo always stays the same before countless of how much im trying to improve. So thats why i need some tips so i can improve and gain more elo. After a few games i improve by doing puzzles and more