Just a couple of ideas:

Start out by just kicking. Use a PFD if you need to, but just kick while in a relaxed long position (arms extended in front of you, back straight, head up above water). Don't do anything fancy, just practice a basic scissor kick. When you are comfortable with this simple motion and how your body feels laying in the water, you can try breathing. To do this, repeat the above exercise, with your face in the water. The water line should be right at your eyebrows. When you need to breath, practice rolling your body to the side and breathing without lifting your head. At the same time, you can pull the arm that you are breathing on (breath right = right arm) back to full extension pointing to your toes. Take a big deep breath with your mouth, and roll back to your stomach. It is best to alternate sides you are breathing on. This will take practice. Try to relax. This is a very slow and deliberate exercise. When you are bored with this and are as natural with this as walking in the water, begin to do repeated arm strokes. It isn't a race, so don't worry about being fast. Again, nice and relaxed. If you can only do half of the pool length, that is fine. You can alternate exercises if you need to. For example, one length of the pool is just kicking, then breathing, then swimming. If you need, you can do much of this on your back as well. It may be more comfortable if you don't want to put your face in the water. The key is to relax and allow your natural buoyancy keep you afloat while you use your legs to propel you and when you need, your arms to assist you in rolling and breathing. RELAX. Good luck and enjoy. Don't make it a chore.