Cardio problems?

Hello!

I started thinking about working out as a small kid. I walked and bicycled from my house and school. And almost everywhere I went in a very peaceful and subtle way. But I felt very weak and uninspired - maybe my problem is a libido problem? Then I started really doubt if I were to grow old because my pulse and I felt like I couldn't go very far. I started really plan so that I could run 5km without stopping and then maybe 10km. But my results are very different from day to day. I try to experiment with different amounts of water but eat a very singular diet (any tips?), I can't really be softy anymore and have to keep running if they bring back obligatory military service (but conditions may let me not to have to make the service, also my friend are mentally ill). For instance i took my winter jacket on today and my results varied again and I felt like diarrhea and vomit. It's like a tiny man or a very aggressive woman screaming in my ear. I said a couple a years ago when I started walking everyday, then intervalls and now I try to run the same slope everyday (but then I got out of time and had to run every 3 days). Any tips to keep a even result everytime (even though I got it alot in a single row maybe two years 11-12 pace 3,5km). Thanks because I might not have time in the future to feel like a failure or pull down my pants inside a bush or wet my pants.

Sincerely TooFriendly112