How can I stop feeling guilty about things i´m not getting done?

Unrealistic goals. Perhaps part of your problem is that you set unrealistic goals for yourself and then feel disappointed in yourself (and guilty) when you can't meet your self-imposed deadlines. Alternatively, if procrastination is a problem, then breaking down tasks into more bite-size (and do-able) pieces might help a lot. Remember: forgive yourself again and again and again. Admittedly, it's hard to do!
Realistic goals. Set realistic goals with reasonable time frames. For the things that cannot get done in the 1st time frame, make a new goal in a new time frame. Go to your final goal like going up a step ladder. Put your guilt to work making a plan to get things done over several time periods. If you are very stressed about your situation or if the suggestion above doesn't work, see a therapist.