<human>: Summarize the given text in a few sentences.

My boyfriend and I have been together a little over a year. He is incredibly sweet, caring, and loving. He loves me more than anything, and would do anything for me. For example, he mails me handwritten letters when we're apart. Who does that these days??  He wants to have a future together, despite the iissues in our relationship. 

  
The problem is me. I am am extremely negative person. I have a supernatural ability to find something wrong with even the most perfect situations. And it has been really effecting our relationship. I am very good with finances, and instead of helping him with his problems (my original intent), I end up criticizing him and telling him how wrong he is with his decisions. He is more than capable of taking care of himself... so I don't know why I do this.  

  
I could go on and on with examples of me criticizing him for just about any thought or opinion or action of his. It's not healthy for either one of us, BUT I don't know how to stop. I want to be a healthy supportive girlfriend. I want to give back to him the love and support that he selflessly gives to me. Instead I show him hatefulness and toxic words... for no reason. I don't know why I say the things I sat and I don't know how to fix my toxicity in our relationship. I feel like there are times when I'm on the verge of being verbally abusive... but I don't want to be at all.
<bot>: Our relationship is under strain because of my negativity and criticism. How to I fix my personal issues so that we can have the loving supporting relationship he works for?