Speak kindly to yourself for your thoughts impact your physical body. (Technically, it's stress hormone production which causes widespread inflammation and long-term damage to major organs...and yes, also affects the immune system's ability to function.)
Don't look past what's right in front of you. If you focus so hard on your "problems," you may miss something great, and trust me...you'll look back with regret later, when that opportunity is gone. Later isn't so far down the road, either.