My first reaction to your post was to ask you to ask yourself a few questions.
Why does your partner feel like that?
Does your partner serve and give you a long ball to attack on 3rd ball, but do you push it back long and allow oppoent to strongly attack?
Do you frequently push the serve long to allow opponent to attack strong on 3rd ball?
Do you serve long and predictable to allow opponent to hit 2nd ball winners?
Those are several valid things that may cause your partner to feel like you are heavily contributing to lost points, which off course add up to a loss.
After reading your subsequent posts and getting a little more data from you about what is going on...
I would agree you have a positive attitude and outlook when things go bad.
Myself, I LOVE playing doubles at my club AND in competitions.
I give my partners the evil eye when they do those things I list above. I play div 2 in my city and you will get killed vs even div 4 players if you do those things. Am I perfect? Nope. You play what you can for your level and work teh best you can together. Usually doubles is real fun. It can suck if your partner is always giving away initive on easy balls and allowing opponets to blast winners. It can be especially irritating if you are an offensive player, but your partner does not provide you 1-2 or even zero chances to attack.
If the two players are div 5 for my city, it is common to push everything (you are not comfortable attacking) and those pushes are not exactly good pushes. It is natural in that situation to give away easy chances often, it is part of that level.
How you and partner feel depends a lot upon you level and what is expected for level of play, tactics, and teamwork.
Sometimes, playing doubles is for fun and socializing, so making chances and executing winning tactics is not always the priotity.
You seem to have a happy attitude and will get through fine.