It's common that learning a lot of new things will temporarily make your rating go down as you try to incorporate the new ideas into your play. Just keep playing and try to use the new ideas without making simple mistakes (I call them simple but of course this is easier said than done).
And also, at low ratings knowledge wont improve your results as much as good calculation habits. By that I mean:
1) After your opponent moves, can you win something with a threat, captures, or check? If one series of forcing moves doesn't win material, try calculating a different move order.
2) What is your opponent's last move threatening? Remember the piece that was moved attacks new squares, but there are also uncovered attacks. For example in the starting position moving the d pawn uncovers one of the bisohps.
3) Before you make your move, imagine it as if it's been made, and check whether your opponent can punish it by winning something with a threat, capture or check.
Even if this process sounds hard... it's probably a little harder than you imagine It takes most people a year or two before they're doing this consistently (the goal is 100% of your moves in 100% of your games). But the good news is the more you practice it the more it becomes a habit, and as you get better you don't have to spend as much energy on this process.
I have tried to expand my opening, middle game, and end game knowledge and felt like I was getting better. I am solving 25 puzzles a day and learning theory but somehow I am not getting better. For every one game I win I lose three. This is obviously very frustrating and as I have worked hard on trying to learn the London and french and expanding my knowledge in the middle game and still losing I don't know what to do.