Just remember to use caution with the pumps - too much, too long can damage your cock. And bear in mind that a cock ring that encircles the base of the shaft only should never, ever be used longer than 30 minutes at a time. And, it should always be sized correctly. Never put one on that is too small for your boner.
If your dick is being squeezed like this before you even get a full hard-on, it's too tight!
Masturbation should be a fun, pleasurable activity and it is not going to be enjoyable if it ends in the Emergency Room.
Despite what some porn videos would lead you to believe, chances are, your dick isn't going to be in any kind of shape for any kind of sex.