As a vegetarian, if you want to include Omega-3 fatty acids in your diet, you should not use fish oil. What is in fish oil mainly comes from fish, and many people may find this unappealing. Instead, consider using flaxseed oil or algae oil which are obtained from plants. The two oils have similar benefits as fish oil but do not contradict with the vegetarian lifestyle.

I suggest you to talk to your doctor about your mother's condition. Based on your mother's condition, he may suggest some different medicine or treatment. And for blisters, making certain lifestyle changes like eating healthy food, taking rest and avoiding certain triggers can prove helpful. 

I can see that scratching you due to a street dog can be a worrying issue for you. From your information, the scratch is not too deep, which may mean there is a low chance of infection. Watch out for any redness, swelling, or warmth around the area. First of all, wash the scratch using soap and water and then apply the antiseptic cream to the area to avoid any further infection. Watch the scratch for a few days, and if you spot any of the infection signs that are getting worse, like more pain, redness, or pus formation, it is better to go to a doctor. 

To avoid blade cut marks, a new wound should be kept clean and properly covered to minimize scars. When healed, apply scar treatment cream or silicon gel sheets regularly to reduce the appearance of scars. Do not expose the scar to sunlight because the UV rays darken it. For more severe or prominent scars it is necessary to refer them to the dermatologist for professional treatments such as laser therapy and microdermabrasion. For the situations with deep scarring, sometimes a cosmetic revisional surgery might be an option but it is always best to seek advice from a dermatologist on individual basis.

You may have a fungus infection in your groin. It may result in scratching and irritation of the affected areas. I suggest you go to a dermatologist who can diagnose and cure your disease.