Odd Erection Promblem

Patient: I get semi-hard erections in the morning. I know longer get random one through out the day. Some weeks are much better than others and they are easier to get. Some are worse almost non exsitent. I am 27 years old and my blood pressure is (mild) slightly higher than average. It has been this way for several months, I use to masturbate frequently but have sense stopped. I have had full erections sparingly though so I don’t see it as any possible physical damage. Sometimes when I am attracted to a women I get a shiver like my body it reacting to it. Is it the blood pressure, Mastubation, or just possibly all in my head. I have started excersicing more and trying to eat better as well. I will go weeks feeling like I am getting over this and then I feel like I am regressing. Any idea what this is?