Pin Head Size Lump On My Testicle

I felt some pain in my right testicle on Tuesday, it soon disappeared. Then last night (Friday) it was feeling a bit painful again after ejaculating, which hasn't happened before. Since it was only the right testicle I had a quick check (even got a warm shower) and felt a small lump about the size of a pinhead. I'm pretty sure it's on the testicle itself - although I find it hard to say where the lump is because it seems to be different (I guess that's just the movement of the testicle) it's near the top, where all the tubes attach, it feels as if there's a tube that actually runs to the lump. I wouldn't say it was painful but when I push or wiggle it, it gives me that kicked in the balls kind of pain, just scaled down quite a bit. Right now I just feel a bit of an annoyance down there, I did masturbate about an hour ago to see if it brought on pain again, but it didn't.

Some additional information: I remember that there was a period, probably around six months ago, when my testicles would sometimes hurt then running, but I thought nothing of it.

I'm in my late teens and now I'm really worried, could barely eat last night after I found the small lump. All of today I've been feeling worried, even bailed out of my plans for tonight. On the one hand I really want to get it checked out especially since I'm going on vacation next week, like with anything, I get overly worried, but on the other hand I do not like the thought of the doctor checking out my balls and I feel really anxious about telling my parents. How can I just go up to my mum and say 'I just found a lump on my balls' would I even say balls? It's just so awkward; we've never spoke about anything like that.

I don't really know why I'm on here. I know that I really should go get it checked out, I also know that I don't necessarily have to tell my parents but I'd rather them know, I think.. I mean I don't even know how to book a doctor's appointment, never mind one for a matter like this.

The thought that this is could be Cancer just makes me feel awful, I want to just say to my self that it's probably nothing, but I can't. 24 hours ago I had nothing on my mind and was looking forward to the weekend, now I can't stop googling this and feeling my balls. Whenever I think to do something to get my mind at rest, such as watching TV or going out I just think NO that's not going to change anything, I know I can't just sit back, but I don't know what to do!