I have very sensitive skin. Ive been using retinol for about 2 month and i stopped for a couple of weeks because i had severe retinol uglies and now im back on it once weekly using moisturizer before & after and it still causes me redness & irritation, so can i use it during the summer with extreme sunexposure ( sun tanning & salty sea) or should i stop for the summer? or incomplete process of retinol usage will cause more harm to my skin?