Positive Attitudes

A few days ago, I got into a little scuffle with my brother regarding my general attitude.  It was sparked by his comment that I was on the whole, rather negative.  Initially I wasn't sure why it struck me so offensively but now that some time has passed, I realize it's because I really do tend to approach many things very apprehensively and I put a lot of pressure on myself.  It can be a good thing and a bad thing. I do very well by holding myself to a high standard of performance and doing everything I can to achieve it.  However, the price paid is a lifestyle of undulating levels of stress, that wreaks havoc not only on my psyche but also those around me.

I certainly don't want to be such a tornado of stress that those around me, especially those I care about most, are negatively impacted, and that is certainly something I want to work on.  I believe there can be a balance between stress derived from desired-goals and a positive attitude.  There's no benefit to be a spitball of stress that no one wants to be around.  As with most pursuits of balance, there is no easy formula.  It's always going to be a work in progress, but as of now, I need to start that work.

After considering ways I can improve upon this, I came up with the following that I can start with:

1. Multi-task less.  When I'm studying, I'm just studying, and when I'm having a meal with my family, that's all I'm doing too.  Giving 100 % attention to each task will not only permit me to be more effective at each respective task but it will also prevent the anxiety/stress of the studying/work from permeating into my family's life. 
2. When I'm stressed, go for a walk or do some yoga.  I don't know about you, but I often feel like my chest is going to explode with anxiety and/or stress.  Sometimes I let it out by venting (which isn't entirely a bad thing), but it's usually not venting to a therapist or willing recipient.  I'm just disowning my stress and putting it on someone else, and I'd like to be able to release the stress and replace it with positivity without hurting anyone else.  Walking and/or yoga and/or deep breathing may do the trick.
3. Complement myself for my hard work.   With high goals and self-expectations, I'm often find myself disappointed and don't give myself a break.   I believe there's a time for self-criticism in order self-improve but self-complementation is just as important.  I can't expect someone else to be my biggest cheer leader. It's gotta come from me first.  

Does anyone else struggle with this? Any suggestions?