How to improve my relationship again ?

How is it that you can't spend time together? Advice will depend on your answer.

For example, if you're a road warrior, then make sure to call and face time as much as you can. If it's because of working late, try having him meet you for dinner near your office. If you work different shifts, then see what you can do together during the times your schedules sync up.

although i am single, i still want to express my opinions
firstly, you can talk to him. having a good conversation is the most effective way to settle a fight. and i think it also can improve your relationship. just spare some time to talk to your husband, expressing your ideas and listening to his feelings and thoughts, trying to cope with this matter collaboratively
besides, do some romantic things for him. for example, give him a bunch of flowers that he likes from time to time. remember to create some surprises in your marriage in order to keep marriage fresh
in addition, in my opinion, if you really like a person, you won't find no time to chat with him and adversely you will try your best to get touch with him. no time is just an excuse. i mean, if you have to work long hours or take flights frequently, you can maintain a day-to-day talk by some electronic devises.

Don't worry, It is happening in the relationship due to office hours, but try to spend some with them and help in other work, help in the kitchen, try to discuss your issues to improve your relation

I agree with a lot of what the others said. You can also call him on the phone once in while, from your job, to reconnect during the day.