Thunderbug,
Hahaha...ur post reminds me of my younger days when i had a serious Crush on my music teacher for 2 yrs!!! Heheehe....
Those were the days....but anyway.....it'd prefer to look at ur problem this way.
1) U mentioned tt u r not too close to ur parents
2) He's living alone most of the time......juz like uHmm...these r 2 impt pts to note
By u/standing them, u'll realize tt the kind of feelings u have for him is "REAL" but not exactly "LOVE". It's highy possible tt u have taken a liking to this teacher due the FACT tt ur parents arent close to u. Well, it is proven tt teenagers who have crush on the Older Guys r lack of attention fr their parents, usually the father. At the same, maybe u'd like to know tt whether or not it's men or women, we tend to look for traits tt r found in our father or mother.
Similarly, umany actually fall for this teacher bcoz of tt.....either he resembles ur dad or may be having a certain trait in him which u hope tt ur dad will possess but yet not 
Another thing is tt u may need to try toking to ur parents abt how u feel, not necessarily abt this Crush but in general, like u guyz need some communication.....they r missing out on a lot of stuffs in their daughter's Life.....tell them u want their attention. Why did i say so?
U r actually "sympathizing" ur teacher coz he's in the same plight as u. U feel lonely for the lack of attention & emotionally-deprived of care & concern......U r having this Crush for many reasons coz he "seems" to u/stand ur situation.......u want someone to share ur Life......someone who has gone thru the same thing. Thunderbug, there's nth wrong abt liking someone who 20 yrs ur senior, as long as Love exists. However, in ur case, i dun wanna make any comment tt u r actually be fooling urself abt this Crush or watsoever....i'd like u to know tt there r in fact other factors tt lead u to experience this Crush...it's not a "pure" Crush....How do i explain tt?...
Imagine u r early for afternoon school but u dun wish to arrive in sch tt early, so u went to the nearby Mac to sit ard bfe time's up for sch. When u r there, u'd be buying a some fries + drink to pass ur time away. Ur intention isnt to get the fries + drink but u still get them bcoz u dun wanna go to sch early. Now, u may be having having an
"unintended" Crush coz u r not able to receive the kind of attention u need at home, so u place the Focus on him.
It's perfectly normal feel this way, even older "teenagers" like us make us silly mistakes......we laugh at ourselves sometimes....hahahhaa
Why dun u cheer up abit, try toking to some counsellors in ur sch who can listen to ur story & be helping u? Update us k? Gd Luck!
