Dear Welcome to HCM We understand your concerns I went through your details. I suggest you not to worry much. The viscosity of the semen is determined by so many factors including water intake, mental state while having sex, stress rate, physical debility, time of the sex etc. Means there are lot of factors which determines the thickness of semen. You just see whether it has the capacity to produce children. Unnecessary worrying about sexual matters induce sexual anxiety which inturn causes sexual debility and weakness. this could be reason for your dark circle under eyes. Do consult a psychologist. Thoughts are there to come and that is the duty of the brain. let the thoughts come. You need to divert the thoughts to more priority ones. Means be busy and divert thoughts. Relaxation and meditation plays an important role in controlling thoughts. Plenty of water, oxygen and exercise most important. For more sexual psychotherapy techniques, You can post a direct question to me in this website. Include every detail as much as you can. I shall prescribe some psychotherapy techniques to control your condition. I am sure that the techniques should be a success. Hope this answers your query. Available for further clarifications. Good luck.