You’re allowed to break down in front of your person. You’re allowed to rant to them about your problems. You’re allowed to show them the sides of yourself you usually keep private.
You shouldn’t feel embarrassed about opening up to them about your past issues or about filling them in on your current drama. If there is a problem in your life, you should feel comfortable discussing it with them. You shouldn’t feel forced to keep secrets. You shouldn’t feel like you need to tiptoe around them and shield them from your problems in order to keep the spark alive.
If you’re in a serious relationship with this person, they deserve to hear what you have to say. They should be there to support you when you’re struggling. They should be a shoulder to lean on when you’re distressed. They should be one of the rare people you know always has your back, no matter how bad things get.
If your person runs away as soon as things get hard, you shouldn’t blame yourself. You shouldn’t feel like you’ve done something wrong. You shouldn’t wish you were less honest and upfront with them.
It’s good that you were transparent. It’s good that you kept them in the loop. You shouldn’t feel pressured to hide bits and pieces of yourself. You shouldn’t feel pressured to lie to them. You shouldn’t feel pressured to pretend everything is fine because they will bolt the second things get complicated.
The right person will be there during your good times and bad times. They will want you around, even when you’re falling apart. They won’t run away when tears form in your eyes. They won’t leave you to deal with your problems by yourself. They will consider your hardships their hardships. They will be your partner, your teammate, your rock. You will get through your rough times together.
If your person isn’t interested in helping you through your lowest points, then they don’t deserve you during your highest points.
After all, serious relationships aren’t always going to be fun and exciting. When you settle down with someone, you’re there for their dark moments, too. You’re going to see what happens when they have bad days. You’re going to see what they’re like when they’re upset. They can’t be happy all the time. They can’t always be in a good mood.
The right person for you will understand that you are multifaceted. You are complex. You can be fun and flirty — but you can also be dreary and dark. You aren’t going to act exactly the same every single day and that’s okay. The right person will try their best to understand you, to be there for you, to encourage you.
If someone runs away as soon as life gets hard, they aren’t going to be a great partner anyway. They aren’t going to be able to support you the way you need to be supported. Without them, you can find somebody new. Somebody who will be there during your good and bad days. 
