Query regarding lifestyle. Advise.

My blood pressure started to fluctuate around July 2017 and used to be around 135/85(few times it has touched 140/90) and still is sometimes is 135/85 rang. I had palpatations as well but they are a lot under control now. I visited a doctor and started taking Ciplar 40 mg once daily and continued it till late 2018. Then I switched to a new doctor who suggested Met XL 25 mg. My BP is well under control now(medicine continued) . I have 2 queries, one is that can i donate blood and other is are there any restrictions when it comes to exercise. I am fond of long distance running(10 km marathon which i will do at most 2-3 times in a year if at all) and also want to do cross fit and gym. Please advise.