Live PL: £1-£2 : 300bb Deep : JJ vs Suspected Big Hand OOP

[LeperLeper]

Hi, my first post, I wanted it to be a good one, but unfortunately it is probably rubbish.

Gone for MSNL because £1-£2 is kind of $2-$4 and it's deep. I think this is a reasonabley straight forward spot which has been covered before, I just cannot find posts about it right now.

So, I'll preface the rest of this post with a warning: I am not very good at poker, but since it's live most of the other people are worse.

On to the hand:
I'm UTG+1 and there's a straddle (£5) so I'm first to act. I have Red Jacks, I pot it to £15.

UTG+2 makes it £40 total. There's been very little light re-raising so I put him on 10 10+, AK, AQ.

Folds to me, I call. At this point should I be thinking I only continue with the hand if I hit another J?

Flop: 4d6d2s

Check, Check. I was suprised by villians check here, maybe he's not got such a strong hand.

Turn: 9d

I check, villain bets £30 in to £88. I didn't know what to make of this small turn bet. Maybe it was some retarded move because I'd shown weakness, maybe he has 1 diamond and is making a ridiculous semi bluff or maybe he's just hit a flush. Even tho pre flop I'd told myself to fold if I didn't hit, I just couldn't do it, so I called. What's your move on the turn?

River: 9s

I check, villian quickly fires out £55 in to £146. Since I'd called the turn, the river hadn't really changed much and it was not a huuuuge bet I decided to call.

I have trouble with quite straight forward situations like this. I often feel like I'm spunking money away by calling down like this, but other times the villian is just playing horrible poker and my hand is a winner.

I appreciate all advice, although I will probably not act on any that involves killing myself because I'm so bad at poker.

Cheers.