Humans have a wide range of emotions, moods, and feelings. In theory, we would like to be happy all the time, but in reality it's not that simple. There can be a lot of pressure to portray a life that is always happy, to prove to others that life is great all the time. That pressure can come from others, or more often, it comes from ourselves.
It's important not to be so hard on ourselves when things aren't going so great. It's easy to get trapped in a cycle of feeling like a failure when even a small thing goes wrong. You may want to "put on a brave face" and not let others know you are suffering. You don't want to be a bother.
However, remember that you are not alone and you are not a burden. Sharing your thoughts and feelings with those you love and trust can lift that weight off your shoulders. It's okay to let others know "hey, I had a shit day and I want to talk about it" or "I'm not doing so great and I just want someone to listen." It's okay to ask for help. It's okay not to be okay.