Regarding your run up, get someone to train with you, get a measuring tape and get a number of markers ( chop the lid of an ice cream container up into four squares, or get something similar) - start your run up from a set position and run in from there consistently, build up to where you feel you've got good rhythym and then go into your bowling action at the crescendo of your pace - get your training buddy to stand near where you're likely to go into your delivery stride and have him place markers down showing where you've gone into your leap and where your front foot lands. Do this six to ten times at the start of your training sessions and then use the measuring tape to mark out the average run up that you're landing on. Do that for every training session until you're used to the distance you need for your peak run up and to get you set, stable and ready to explode through the crease
Regarding bowling speed, a lot of it is natural, but doing Push Ups, Burpees, Jumping Squats and Medicine Ball work outside of cricket practice to build up the strength and explosiveness you'll require and assist you to find an extra few kilometers. Kettlebell work also works but you'll need a proper personal trainer to help you with what to do and how to do it.
The next thing will come down to analysis of your action - if you can, get someone to film some of your deliveries from behind, side on and infront of you. You'll be wanting to focus on your follow through being straight towards the direction in which you're delivering the ball in your first few strides, you'll want to be timing your front arm to be pulling toward you at the same time you're bringing your bowling arm over and you'll want to work on your arm coming through and propelling you into your follow through stride. Once you've got some video analysis, check for areas of weakness - i.e your head position, how high your arm action is, if you fall away during your delivery stride, how straight those first few strides are in your follow through, how consistent your load up and release is and then go through at walking pace how you want to setup your action and then jog it through, slowly bringing the speed up until you're feeling comfortable.
Obviously much easier if you've got a good judge of a bowling action and someone who can help you with the triggers.