"How do you stay motivated and not have doubts about your abilities? Sometimes I can get very easily discouraged and sometimes that makes me want to give up." - RSR Winter Athlete
I appreciate this honest question and I am sorry to say that you will probably never "not have doubts about your abilities." Everyone has doubts about their abilities (except maybe super narcissistic people) and it is totally natural and normal. That said, you want to make sure doubts have only a small place in your mental head space and do not dominate that mental space.
I have and continue to have doubts about my abilities, but I learned to train myself to ensure those doubts (or that voice, usually the "negative voice") are quiet or that I at least let my positive voice have the last word. You know the saying, "Everyone has a positive dog and a negative dog in their head. Which dog wins the dog fight? The answer, the one you feed." I really like this- because you have to regularly, systematically and consistently "feed the positive dog" on a daily basis. This is how you train grit. It's every day. Hard work. Positive attitude. Being grateful. You want to train your brain to let the positive dog win more often.
Once you start thinking about this you will find yourself focusing on the day to day (not on a year-long scale) which is more digestible and not as intimidating. People get distracted in their training because they are worried about something they already did or something they will have to do in the future. Focus on what you are doing RIGHT NOW. WHAT CAN YOU DO TODAY TO REACH YOUR GOALS? I like to remind folks "You get stronger or weaker every day with every decision you make. DECIDE to get stronger." One of those ways may be to reduce the negative self-talk. Once you focus on what you are doing RIGHT NOW you will find that you don't have room to think about what you can or cannot do in the future.
My favorite definition of "mental toughness" - the ability to focus on the NEXT most important thing you have to do - not what just happened or what is going to happen, but what you are doing RIGHT NOW. If you do that, you will find you don't have time to doubt because you will have to focus on the stroke you are one (not question your ability for the stroke 100 strokes in the future). Think about a basketball player who misses a shot, the most mental tough athletes are on to the next play they are not wallowing about how they missed a shot they are after that rebound.
I just interviewed a recent Princeton rower and I asked her, "What do you think about on the starting line" expecting her to say something about reminding herself of all the work she had done, that she was ready, that she was going to win... Do you know what she said?
"I tell myself to take my best first stroke." Awesome.
Focus on the immediate task at hand and focus on doing it to the best of your ability. The more often you do this, the easier it will be and the more natural. And as you can improve your focus and execution, you will see that you CAN actually do it and the confidence continues to build. You can always take ONE MORE STROKE- focus on the one you are on ONLY.