Hugs, Ramya!! A lot of us are right there with you in mid-season funk!! It is easy to get bored of the things we have when we have to wear them again and again the same way for weeks on end.
As for the other elements, if it's not mid-season funk, for me it can be what Angie said:
1. Don't have the "glue" items that make true outfits.
These actually take longer than you might expect to discover and implement. What they are will differ from person to person. For me, they are shoes/ footwear, belts, and toppers, although this year I am shockingly short on toppers. But that might be different for you. For some people it might be scarves, or jewellery. Or...sometimes people have a wardrobe of "star" players without enough simple essentials to tie it all together. Or vice versa -- only the simple pieces without enough interest.
2. Often I feel like this just before a needed style shift, as others have said.
Gigi is also right -- I try to have smaller "capsule" wardrobe to prevent boredom. But not in the winter, per se. Winter is such a long season for me, I have all my cold-weather clothing out on view from late October until late March (at minimum). I layer with the lighter weight sweaters at that time. The "capsule" part comes in late winter/ early spring (March/ April for me) when I will switch out some of the darker colours and add a few items in lighter colours and neutrals but still warmer fabrics, and I will put away the really heavier woollens.
Hang in there! You'll get sorted!