I've looked at some of your losses. 2 major issues are apparent.
First, your time management is bad. You play way too fast for someone who is struggling with tactics.
Take your time. Look at possible checks and captures (for you and your opponent) during every move. Yes that's annoying to do that during every move, but with the amount of 1-move blunders you need to do it.
you lose with 22 1/2 minutes left of your 25 minutes. Hung a simple fork.
you just hung your queen, moving it to where a knight can just take it.
hanging mate in 1 twice in a row with 8 1/2 minutes of 10 minutes remaining.
If 25 minutes isn't enough, increase your time control. Be patient.
Second, you seem to do the mistake most beginners to intermediate players do. You exchange pieces when the opportunity arises. This should become better when you take your time for every move.