What do you do if you keep on losing in bullet?

I think this needs to be qualified. You don't learn much that helps you play chess at "normal" speeds by playing bullet.

When I first started to play bullet on chess.com I got very annoyed that in game after game I would outplay my opponent completely,  yet lose in objectively won positions because the opponent had used anything from a couple of seconds to a fraction of a second less than me.

After a while I realised that such annoyance is unjustified. Bullet and slow chess are different games!

In slower chess you win by avoiding bad blunders, seeing more of the tactics than your opponent, knowing what to do about positional advantages and disadvantages and good planning.

For super-strong players, who have very fast sight of the board the same methods work in bullet but at less-than-elite levels the skills that make you good at one are not the same as those that make you good at the other.  Skill at slow chess can even be a handicap leading you to play too slowly for bullet.

The way we less-than-masterly players can get good results at bullet is to play faster than the opponent  while avoiding making such bad blunders that we can easily be checkmated us while overall. Another useful skill is to play moves that are unexpected and make the opponent think for a second or two. To that end even absurd moves that would certainly lose in slow chess can win the game for you.

Can bullet chess help improve your game at slower speeds? 

I think it can.  For me it has shown me that my sight of the board is too slow, and I suspect this is a factor in the oversights and blunders that I make at slower speeds.  I believe that playing bullet could help us to see what is happening on the board more quickly.  I have yet to see if it leads to any improvement in slower games, but the possibility ought not to be ruled out on the basis of some prejudice or intuitive ideas.

Of course if you carry the "bullet habit" of moving quickly without making a careful  blunder check before each move then playing bullet will mess up your skill at slower speeds.

I still suck at bullet on-line.  it is much easier to play when you have a real board and pieces and do not have to fiddle with a mouse,  trackpad or joystick, or suffer from network delays.  I find it almost impossible to make more than 40 moves in an on-line bullet game.   That is to say it takes me about 1.5s per move, even when I think I am responding instantly.  With a real board and pieces and I can easily play 80 moves in a bullet game, and still seem to have more thinking time.

There is another way that bullet can help to ikmprove at slow chess. To cash in a strong position at bullet it is not enough to win material, then patiently exploit it ... usually in an ending.  It takes too many moves.  Much of the time the only way to get the full point is to force checkmate in very few moves.  So learning to spot typical mates and acquiring the skill to play them out quickly will improve ability in chess at whatever speed it is played.

Try to wake up in the evening ?

It is the same if I wake up in the evening. My brain still is asleep.

Then when you wake up:

1 - Make 2 minutes of jumping jakes exercises.

2 - Make 40 arm pushups.

3 - Drink 3 cups of coffee.

Then you can play your blitz games. I am sure you'll be awake.

This is bullet.

 Stop getting up in the morning?