Not liking my class but loving my character.

So in a game of 5e with my friends I decided I wanted to play the alchemist subclass for artificer. I had never played the artificer and the idea of a potion maker sounded really cool. However at the time I didn't realize alchemist was a rather boring class. So here we are five levels later and I'm enjoying my character in the campaign and I've started multi-classing into rogue a little bit however I'm really not enjoying the artificer(specifically thr alchemist) stuff as much.

I'm thinking of asking why DM if she will let me put levels into just a different subclass of artificer. Because being only a level 3 rogue And then having four levels in a class that I'm not enjoying and aren't really using the features for makes me significantly weaker than the rest of the party. However the Dm is a rather new DM and the rest of us are pretty experienced in dming. I don't want it to seem like im wanting to change subclass for the sake of being stronger or anything. I just want fo make my gameplay more fun.

So my question to the community is What should I do?